Top Circuits Page 70
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Most portable systems have built-in PCMCIA sockets as
the sole means of expansion. The requirements of the
PCMCIA specification have led to some confusion among
system designers. This Design Note will attempt to lessen
the confusion and highlight other....
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The circuit of the mains current detector is shown in Figure 1. By using a few cheap diodes, a resistor, LED and LDR, a simple opto-isolated detector can be created. This entire circuit dissipates very low power, and can safely be housed in a heatshrink....
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You can easily improve on a previous Design Idea to produce a slightly simpler resistor arrangement with better timing balance between switches, using a single resistor value (Reference 1, Figure 1). The use of a single resistor value, RS, in a series chain....
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Circuits that latch one-of-N switches usually use a digital approach. Such circuits are often useful in human-interface situations, such as audio-mixing consoles, video-feed selection, or current-loop-control redundancy systems. In high-precision analog....
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Digitally controlled potentiometers are useful for generating analog control voltages under the control of a microcontroller. In some applications, manual pushbutton switches could replace a microcontroller and simplify product design. Mechanical switches....
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At times, a µC must read a large number of DIP switches, such as for system identification, bus-address setup, manual configuration, or other purposes. However, the available number of I/O lines is sometimes not enough to assign a switch to each one. You can....
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Some machines need to run for long periods and therefore may finish their work in the middle of the night or during the weekend. For the time remaining, until the operator returns, the machines stay idle, uselessly consuming power. This Design Idea allows a....
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Designers of microcontroller-based products that require a keypad for user data entry can select from dedicating an input line for each key, continuously polling the keypad`s x and y lines, or generating an interrupt whenever a user presses a key. Although....
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Many power-supply designers like to have a regulator latch off in the event of an overcurrent situation or other fault condition. Yet, many PWM controllers do not internally support this latch-off function. Most do, however, have a power-good output and an....
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When the "ON/OFF" button is pressed once, the equipment goes on and stays on. It goes off when the button is pressed again. The circuit is straight forward. It uses a JK CMOS FlipFlop to with its JK terminals tied high to achieve the toggling action. The....
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The delay time for all circuits shown has been revised. The optimum is around 100ms - sufficient for around 5 full cycles at 50Hz, or 6 cycles at 60Hz. It is also quite alright to run the transformer to around 200-500% of full load current at start-up, and....
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This circuit will remove the transient spikes and contact bounces from a non-latching push button switch. Using a 555 timer as a monostable circuit, it is easy to build a good switch debouncer circuit. There are many circuits for SPDT debouncing, but not....
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This sensitive sound operated switch can be used with a dynamic microphone insert as above,
or be used with an electret (ECM) microphone. If an ECM is used then R1 (shown dotted) will
need to be included. A suitable value would be between 2.2k and 10kohms...
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You may be familiar with this effect. You switch audio equipment such as an amplifier to a different input and there is a loud click or "thump" in the speaker system. Not all equipment is affected. Some high end audio systems never suffer, but intercoms....
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The MPF102 (Q1) can be replaced with a NTE451 or ECG451, but still widely available. JFET-N-CHAN, UHF/VHF AMP. The 2N3565 (Q1/Q2) can be replace with a 2N2222(A), BC107, BC108, BC109(A/B/C), NTE123A, or ECG123A. The TIP31 (Q3) can be replaced with a NTE196....
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Dual Channel Relay Board is a simple and convenient way to interface 2 relays for switching application in your project. Input - 12 VDC @ 84 mA. Output - two SPDT relay. Relay specification - 5 A @ 230 VAC. Trigger level - 2 ~ 5 VDC. Berg pins for connecting....
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This project describes how to build a "soft touch" switch. By "soft touch" we mean that you have to push once to set device ON and push again to set device OFF. This kind of switch works by latching a relay to ON state with push of a button and with another....
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Just the solution for AVR applications in which I/O is tight, such as the ATtiny12. This should work well on other kids of controllers that have independently controlled I/O direction registers, such as PIC and 6805 controllers. This is a solution was....
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The main box of the Transmit Selector system is designed to be located in the technical rack of a small radio broadcast station. There are four stereo balanced line inputs, either of which can be routed to a stereo balanced output. The signal routing is....
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The purpose of this circuit is to automatically turn off any device plugged into its power outlets after a certain period of time. Shutoff is activated by an absences of an audio signal or by a standard timer function. This unit would be connected to speaker....
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Using a switch to power up your microcontroller projects may not be a good idea if you need to "wake" the PIC during some events. For example: A metal detector sends a pulse indicating a car is ready to enter into a garaje, so the user needs to type a....
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As with the Electronic sel. 8 we also have here a circuit with a choice of 8 different sources. The difference is that only two of the switches are used and the movement of commands is Up-Down in series. We have evidence of activity at each entrance by the....
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Here we have three choices, with which we can make electronic switches that use our touch or pressing (push button). We thus exploit the very big resistance of entry, that present the gates CMOS. In the fig.1 we have two gates NAND or NOR (IC1), connected as....
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The Elect. Sel. 8 is a simple circuit, with a choice of 8 sources of any sort ,of 8 independent switches. Each switch corresponding with a relay for example the switch S1 activates the RL1 e.t.c. The uses of the circuit are quite a few, choice of entrances....
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This is a circuit for alternative sources selection. It combines mechanical selection using a rotating switch S1, the electronic drive of the relays RL 1-10 and also the optical indication of the selection by the Display DSP1. The function is based on the....
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A voltage window switch is in practice the basic lower window limit of this circuit is roughly 3V and the upper limit is 9V. The window range can be extended by fitting a suitable range
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Described here is a very inexpensive solution to many phono-controlled applications like remote switching on, for instance, or activating a camera, tape recorder, burglar alarms, toys, etc. The circuit given here employs a condenser microphone as the....
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Using dual flip-flop IC CD4027 employ a 555 based monostable circuit to supply input clock pulses. The circuit described here obviates this requirement. One of the two flip-flops within IC CD4027 itself acts as square wave shaper...
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An infra-red or wireless remote control has the disadvantage that the small, handy, remote transmitter is often misplaced. The sound operated switch has the advantage that the transmitter is always with you. This project offers a way to control up to four....
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One of the more frequently requested projects on HeadWize has been a switchbox for selecting multiple audio inputs. I built this passive preamp/switchbox several years ago to switch between two stereo sources (a portable FM tuner and portable CD player) AND....
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This project couldn't be any simpler if it tried. Using the PC's internal 12V supply to operate a relay, it is 100% reliable. If the PC is on, the peripherals are on and vice versa - it can't be otherwise (unless the relay fails). Other solutions have been....
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This project is useful if you wish to experiment with absolute phase, or are just interested in the possibilities of a polarity reversal circuit. In the case of absolute phase, many studies have shown that there can be an audible difference between....
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Touch operated switches are an attractive project for DIY electronics but they are not so common in commercial products. The reason for this is that, although there are many different ways of implementing a touch switch (leakage, hum pickup, capacitance,....
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Just to prove that transistors can also be useful in logic situations; this is a data latch and indicator which also is a data switch and has a bidirectional input/output port which can be read or switched. If the second transistor is off, a small currrent....
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The circuit below uses a CMOS dual D flip flop (CD4013) to toggle a relay or other load with a momentary push button. Several push buttons can be wired in parallel to control the relay from multiple locations. A high level from the push button is coupled to....
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This circuit toggles on and off a NE555 with a single momentary switch. Unlike a mechanical bistable relay the circuit backs to the start condition if you switch off the power supply. No relay contact is used...
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When the touch plate is contacted by a large object (human body, etc.), stray 60-?? pickup is rectified by D1 and D2, and produces a negative voltage across R2-C2 and the gate of Q 1. Q1 cuts off, causes Q2 to conduct, and the output goes low. ..
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Circuit switch S is closed after the integrated circuit TDA1024 trigger is turned on. Whenever the zero crossing of the mains ..
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Fig. 296 can use a control switch S El, E2 and E3 three lamp light off. E is suitable for the living room chandelier control. When s off, lights all the fire; for the first tim..
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FIG switching solenoid driver circuit, wherein the device chip U8 is 74123, the device is a solid state relays 02, 03, the switching electromagnet coil is sucked PUSH coil, HOL..
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End a two-wire connection gradually clear/fade switch circuit when the circuit is relatively simple to install. Turn on the lights when needed, H properly switch S dial upward,..
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Electronic CD4017, CD4066 constitute the switch circuit diagram: ..
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Do not trigger circuit thyristor AC switch circuit, due to its simple, economical, non-contact, so widely used. Circuit shown in Figure 16-43. It is a single-phase thyristor sw..
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As shown in the circuit to light when the intensity 700lx above action, this time through the ..
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MIC5158 constitute the rising edge of the high-speed switching circuit diagram...
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A. B, C for big power split phase I, A + B'C 'Rang generator phase line, A-A' indole path string has a 2H220V / 15W bulbs, bulbs recovery as both macro instructions J Sweet World as Well buck's electric brake sheet J. W Lamp wooden pole end....
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AC-DC power supply without power switching circuit normally used for lighting load circuit, once the power grid or power is restored, the standby power supply automatic switchi..
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Analog switches sl and sa disconnect, Ctz the inverted logic signal to terminal 2 s! And 84 is turned on, so that prisoners capacitance between S1 and S 8 and coupling will be ..
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As illustrated, the switch circuit by capacitive oscillator, the integration network, and a comparator circuit relay control circuit. When the body close to the induction metal..
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As shown Multifunction leakage protection switch utilizing Nissan ASIC M54122L, it can be composed of multi-function leakage protection switch, when the leakage and electric sh..
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As shown in FIG Multiport W723 is being integrated adjustable constant current regulator composition application switching regulator circuit, the output current of 1A. Illustra..
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As shown in FIG TOPSwitch FZ chip switching power supply circuit diagram is controlled by the MCUs. The microcontroller can use inkjet printers, laser printers and other comput..
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As shown, the count switching circuit comprises an electronic switch and a pulse delay circuit control. ..
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Automatic cycle switch circuit 2 It uses 555 IC as the control element} A capacitive step-down circuit; bidirectional thyristor V control relays or loads on and off time. RPi a..
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BT9404 de-excitation type switch by the CJ4-S contactors and JT3-21/3-type electromagnetic relays. Its control circuit is shown in Figure 7-55. Figure, KM contactors CJ4-S; KT ..
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Because the loop gain of the amplifier OP depends mainly on the dry input resistor and feedback resistor ratio, so the resistance error, an error occurs opening will be a corre..
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Figure 16-48 (a) for the introduction of six thyristor three-phase AC switching circuit; Figure 16-48 (b) as adopted by three triac circuits. Suitable for motors and other indu..
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DC voltage of the generator field winding by a three-phase thyristor rectifier provided later. In the same period incorrect, out of step, system failure, etc., the rectifier wi..
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# The circuit can produce about 250-500mA at 2KV, depending on the transformer.
# For C1, you can use the capacitor out of an old microwave.
# This circuit is mainly provided as a demonstration of using commonly available parts for something uncommon.....
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The circuit in Figure 1 can drive high-resistance, low-capacitance piezoelectric loads at a 3-dB bandwidth of 6 kHz. It offers a low-cost alternative to commercial drivers...
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The circuit uses fast transimpedance amps, "floated" at 70V. Two "virtual-zener" circuits step down the high-voltage signals for subsequent processing in a ground-referred differential-amplifier stage (Figure 1). The circuit drops exactly 65.58V dc with the....
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The circuit in Figure 1 generates 100V from 25V. The circuit is a typical flyback regulator that uses a couple of well-established circuit techniques to handle the high voltage...
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The Electronic Dazer is a modern, portable, personal-protection appliance. It generates hight potential energy to ward off vicious animals or other attackers. It is an aid to help exape from a potentially dangerous situation. the device develops about 2,000....
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The peak output voltage will be approximately 15,000 to 20,000 volts, but this will vary with the ignition coil type and the voltage at which the MOV starts conducting. Do not touch any part of the 555 circuit including any leads of the timing resistors or....
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This Design Idea presents a simplified ac high-voltage amplifier that uses complementary, cascaded NMOS and PMOS transistors (Figure 1). The OP07 op amp has low input-offset voltage, low input-bias current, and high open-loop gain...
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The TPS61040 is a highly integrated, low power, boost converter capable of delivering
output voltages up to 28 V. However, using a coupled inductor enables the TPS61040 to
be used in applications where higher voltages are required. Output voltages up to 75....
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It will supply 15 watts of AC power to a device. It should power lamps, shavers, small stereos and small appliances. If you draw to much power the circuit will shut down all by itself. The output of this circuit is a square wave so there may be some....
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One very important Part of a Tube Amplifier is the Power Supply. It is crucial for the quality of the whole system. Especially beginners encounter problems like Hum or Drift that can become quite annoying. But resue is ahead: The following circuit uses a....
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The circuit in Figure 1 uses a fully differential amplifier to offer an answer to this problem. Fully differential amplifiers enable you to deliver an output-voltage swing beyond the rails into the load. One of the common problems in working with operational....
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Designing a high-voltage switching power supply that can produce a sustained arc can be challenging. This compact and efficient design delivers 1 kV at 20W and can withstand a continuous arcing, or short-circuit, condition (Figure 1). It uses standard,....
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This is a High Voltage switching device for driving coils and which have big impedance when it is switched off. It can be use in Back-EMF energy recovery tests, Newman coils electronic commutator.....This device is drived by an opto-coupler and can be easily....
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This High Voltage power supply is able to generate up to 25-30kV DC Output from a 12-24v DC input. With a fully adjustable DC input power supply (0-24V/4A), it is possible to adjust the HV output between 5 to 30kV. This HV power supply use a common flyback....
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A 555 is used as an oscillator, optimally around 15.76KHz (in North America). Power pins on the chip (pin 1 to ground, pin 8 to +12V) are not shown on the diagram. The output from the 555 is then switched by PNP transistor Q1 and by the large 2N3055 NPN....
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It still uses a transistor to do some switching, and it still needs a pair of diodes and capacitors, as would be used in a conventional multiplier, but it doesn't require a steady stream of pulses and the output voltage is set by a resistor divider as the....
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The 555 is wired as an astable and the capacitor is charged only through the 4,7Kohm trimmer (notice the diode) and discharged only through the 2.2 Kohm trimmer, making the duty cycle full adjustable. The square wave is then feed in a totem pole made up of a....
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A basic mains driven Cockroft ladder high voltage generator is shown in the schematic. This is functionally the same as a project in Electronics Today International many years ago. The peak mains voltage of 340V appears across each capacitor and this is....
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This device uses a PIC12F615 to implement a capacitor discharge ignition system. When the switch (button) is closed, the PIC sends pulses to the IRF644 MosFet creating high voltage pulses to charge the 1.0 uf/250 volt capacitor. The voltage is read back via....
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This stun gun is powered by a 9V battery. The transformer steps up the voltage to about 1800V (but with very low current). A 555 timer IC is used to generate a high-frequency output. A 1 MEG variable resistor can also be used at the output to drop the....
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This Spark Can Be Very DANGEROUS, So BE CAREFUL. WARNING: FAILURE TO DO SO: WILL CAUSE THE CASE OF THE COIL TO ALSO BE ELECTRIFIED! NOTE You MUST have a LOAD on the High Voltage Output. With NO LOAD, you have a High Risk to "Damage the Ignition Coil". Either....
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A Very Low Current, High Voltage Spark, that is "Manually Triggered". Although its not easily Measured, the Peak Ouput voltage will be over 5,000 Volts. T1 is a small audio transformer and it steps up the voltage to about 500 Volts at Point "X" on the....
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A Simple design based on a 555 to Drive a Car Ignition Coil. I Designed this for a Small Electric Fence to Protect my Vegitable Garden from some Small Animal called a Marmots. Last year they ate one of my crops entirely before I could install this device. A....
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A circuit design, based on a C-mos chip to Drive a Car Ignition Coil. This is a Very Simple and Efficient Design for an Electric Fence. It puts out a Very high Voltage Current pulse, yet it draws a very small average Current from the battery or supply. As....
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Easy to build, this high voltage generator is capable of generating up to 50KV but the breakdown voltage of the coil limits the voltage to a value somewhat lower. T2 is the ignition coil of a car and also the 0.5µF capacitor comes from the same place:....
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A high voltage power supply is a very useful source which can be effectively used in many applications like biasing of gas-discharge tubes and radiation detectors etc. Such a power supply could also be used for protection of property by electric charging of....
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Single transistor flyback driver caused many problems due to it's operating principle. I received e-mails from people who were unable to get it functional even when they are sure that their flyback and transistor is OK. In addition, since it's resonance....
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The 555 is wired as an astable and the capacitor is charged only through the 4,7Kohm trimmer (notice the diode) and discharged only through the 2.2 Kohm trimmer, making the duty cycle full adjustable. The square wave is then feed in a totem pole made up of a....
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The CDI ignition circuit produces a spark from an ignition coil by discharging a capacitor across the primary of the coil. A 2uF capacitor is charged to about 340 volts and the discharge is controlled by an SCR. A Schmitt trigger oscillator (74C14) and....
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This high-voltage power supply has an inverter around Q1 that supplies 150-V pulses to the converter of SCR1 and C2. The output of ?2 is a 4.5-kV pulse that is multiplied by the voltage-tripler network (right) to produce 13.5 kV.
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I found the following schematic from online sources. It’s about generating and launching ions. I did not built this circuit. But I’ll present some ideas on how to focus ions so that they will travel a longer distance. ..
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A commercial stun gun circuit which produces about 100KV pulses from a 9V battery is shown in Figures 1-2. The heart of the circuit is a power oscillator built around Q1. When the switch S1 is closed, C1 is charged through 1K resistor and the feedback coil.....
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The circuit described here uses an IRF840 MOSFET which is rated at a maximum DSV value of 500V. The avalanche voltage is calculated as 36501. max DSA VV V. This means that up to about 600V of inductive kickback voltage may develop in the switched coil.....
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I've designed a high-voltage generator which uses a flyback transformer as the output stage. Flyback transformer circuit diagram is shown in Fig. 1. And I like to share some of my findings with you. ..
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Carbon arc beam was used extensively as searchlight during WWII. Fig. 1 shows a basic configuration. Basic beam generator can be modified as shown in Fig. 2 so that high-voltage (HV) electricity rides the beam. This design has never been tested. ..
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Expanding schematic circuit secondary circuit high-voltage lines ..
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The south circuit composed of four parts, the order of descent {NPN transistor whole dynamic garbage dog device (Tfl ", Tr ..
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As shown in FIG. 1 circuit generates high voltage signal for controlling BST (barium strontium titanate) capacitors capacitance. Simply applying a voltage of V and 3V to the co..
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As shown neon voltage power supply circuit. Its production is simple, stable output power and other characteristics. Circuit Principle: The core element of this circuit is the ..
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As we all know, high-voltage isolation switch is not allowed to meet with a load that would otherwise produce arc, causing a short between the high voltage bus road accident, e..
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Circuit is shown. Normal driving transistor would need a higher breakdown voltage transistor (FIG driving tube 9013). When the output voltage increases, VT55 bias increases, B5..
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This circuit is very basic to build. To open a the lock which is connected to the K1 Load you must press each momentary switch in the correct sequence. The sequence used in this circuit is S1,S2,S3,S4. If any of the other switches are pressed the circuit....