Top Circuits Page 249
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IC1 generates 150 µSec. pulses at about 80Hz frequency. Q1 acts as a buffer and Q2 inverts the polarity of the pulses and drives the Transformer. The amplitude of the output pulses is set by P1 and approximately displayed by the brightness of LED D1. D2....
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The 8-lead plastic mini-DIP LM3909 IC was developed by National Semiconductor in the mid `seventies of the past century. It was a monolithic oscillator specifically designed to flash Light Emitting Diodes. By using the timing capacitor for voltage boost, it....
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you could apply a step sequence that only triggers every other step, then, make the steps that do trigger, rise with each activation. From there you could apply that LFO to other parameters of the plugin to spice up the sound. (I. e. you could apply it to....
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-
-
This controller is essentially 3 pairs of LED sensors in a 3G -bridge configuration. The driver is capable of operating 3 actuators. The motors are connected in a Delta configuration. The apexes of the delta are connected to the center connection of each....
-
This program includes circuit design cad, simulation, and auto routing PC layout. I also use PSPICE at Unisys which has more capabilities but costs 6 times as much and needs to be renewed yearly. With these requirements in mind, and some others, I decided on....
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The above table is useful to determine the capabilities of the MOSFETs for the various versions. However, the connectors I have used on the LED3X "c" series is not rated for such high currents on a continuous basis. The connector is technically rated for 7....
-
-
The output level was set to 3. 8V peak to peak, not for any good reason, the first aim was to compare a few different op-amps before trying to further optimise the circuit. The op-amps were TL072, LM4562 and OPA2134. The distortion spectra are shown next, in....
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It`s basically a standard Hartley oscillator, output is +7 dBm into 50 Ohms. Don`t be tempted to add a gate diode, this circuit doesn`t need it, and it will degrade the phase noise performance, according to Ulrich Rohde. It should be suitable for any....
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To be used with PC connected to video projectors, where the lighting controller may require control of a presentation on the video screen but the PC for the presentation is located in a different location to lighting control. The Hardware required for this....
-
Connect a 12 volt 20 watt lamp and 12 volt battery to the circuit (observe battery polarity). Momentarily press and release the button to turn the lamp on. Repeatedly press the button to cycle through the power levels. Pressing and holding the button will....
-
-
This is a collection of various useful and interesting schematics. Some of these are also referenced by or included in other documents at this site. What isn`t here (this may not be everything): * Extremely important safety information. See the document: "....
-
-
-
The use of electrically excited gas discharges significantly predates the invention of the incandescent lamp. Physics labs of yesteryear as well as today have use of a variety of gas filled tubes used for numerous purposes involving light generation....
-
-
The high voltage power supply was probably good for 12 to 30 kVDC at 1 or 2 mA. This is useful for many high voltage experiments, plasma globes, negative ion and ozone generators, bug disintegrators, starters for really LARGE HeNe lasers, etc. The devices,....
-
This chapter provides detailed schematics of a variety of power supplies suitable for use with the common Ar/Kr ion tubes available to the hobbyist on the surplus market. Included are examples of commercial designs (Omnichrome 150R and 532 head, Lexel 88 and....
-
-
The carbon dioxide (CO2) laser is the powerhouse for high tech industrial cutting and welding of metals and many other materials. Small CO2 lasers are used for marking of metal, wood, and composites, and in medicine and surgery. Even a `small` CO2 laser....
-
-
The Pulsed Multiple Gas (PMG) laser described in this chapter is very similar in many ways to the Home-Built Pulsed Argon and/or Krypton (Ar/Kr) Ion Laser from Scientific American. However, the developers of the PMG laser have also used it with xenon (Xe)....
-
Many areas of scientific research and industrial production require vacuum conditions - where most (or as much as possible) of the air has been removed leaving little or nothing behind. While written specifically for the needs of home-built gas lasers, much....
-
This includes immunity to power line transients as well as those that may occur during power-on and power-off cycling. The parameters of many electronic components like ICs are rarely specified during periods of changing input power. Special laser diode....
-
This chapter provides a variety of circuits of both line powered and inverter types for the basic power supply, some with regulators, modulation inputs, and other goodies. Several have been reverse engineered from actual working commercial products. Some of....
-
This chapter contains circuit diagrams for several power supplies for pulsed solid state lasers. These include units suitable for driving the popular Hughes ruby and YAG rangefinder laser assemblies as well, one using the flash from a disposable pocket....
-
-
-
-
All of ACC`s repeater and remote base products support control of synthesized remote base transceivers. One form of frequency control supported is compatible with transceivers using thumbwheel frequency selection. The controllers supply BCD (binary coded....
-
Those of you who own large 500 watt and higher Astron linear power supplies, and even large HF amplifiers, know all too well that "GNNNNnng" sound that they often make when turned on. This is due to the high inrush (surge) current flowing into the....
-
This article provides conversion instructions for radio model # GE/MACOM MASTR-III Group 2 (150. 8-174 MHz) Repeater or Base, Combination Number SXS, to allow it to perform adequately in the 144-148 MHz range. Please be aware that this document is currently....
-
The artwork style of the opamp and of the meter face both suggest that is is an ACC design and is from an old issue of ACC Notes. I have credited it as such. I scanned the second image and wrote the text below from scratch. If anybody can locate the original....
-
This is a detailed explanation of a procedure you can use to modify a UHF MICOR "M" range (450-470 MHz) receiver board so it operates adequately in the 435-450 MHz range. This is an enhancement to Kevin`s text-only article. These receivers are commonly found....
-
-
-
Here are two photos of the interior of the NSN6054A. The two metal brackets that hold the circuit board in place also function as heat sinks for the 12 watt audio amplifier...
-
Many of us who use GTX 900 MHz radios to work amateur repeaters are well aware of the erratic output power problem. You go through the complete board replacement procedure, adjusting the deviation and output power, and everything looks great on the test....
-
The regulated output voltage varied as the unregulated DC voltage changed, and that changed as the load current or the incoming AC line voltage was varied. There was no easy fix to the existing circuit that would solve this problem. Eric WB6FLY had already....
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This article describes one reliable, simple, and universal method of interfacing MaxTrac, Radius, and GM300 series of Motorola mobile radios to common repeater controllers. Most of this information also applies to radio interfaces that are used with IRLP or....
-
This page is oriented towards the USA marketed radios, simply because it was compiled by USA residents; we described the radios we are familiar with. If anyone would care to share information on the non-USA radios we`d be happy to add them on this page, or....
-
This article provides an overview of the R100 and MCR100 UHF repeaters. All of the information came from physical examination of the station and running the programming software, as well as the R100 Instruction (and service) Manual, p/n 6881078E15 and the....
-
No matter WHAT the label on the radio (or the seller) says, no Spectra will ever operate over the entire 136-174MHz (high band) or 403-512MHz (UHF) frequency range. Each unit will do only a portion of that band`s frequency spread, and that portion is called....
-
To build a GaAs FET preamp that has good gain and extremely low noise from readily available components. This preamp is stable with differing source and load situations. The circuit is built dead bug style on a piece of printed circuit board for a good....
-
-
This page deals with the subject of replacing the crystal in any type of Temperature Compensated Crystal Oscillator (TCXO), be it a Motorola "Channel Element", a GE "Integrated Circuit Oscillator Module" (commonly called an ICOM), or an RCA TCXO. Here we`re....
-
-
Another super-simple circuit. You could use this circuit to drive a low power speaker from a sound effects module or a noise generator. Or you could build your own amplified speakers for use with your computer. As shown (with no gain setting network between....
-
If your stereo amplifier does not have an input for a record player, you should use this circuit between your turntable and your amplifier. The output of your turntable follows a gain-bandwidth curve called the RIAA compensation curve. The standard AUX input....
-
This is a classic 2 transistor astable multivibrator. Many other NPN small signal or switching transistors can be used, including 2N4401, PN2222 or 2N2222 using the circuit on the left. The circuit can also be inverted using PNP transistors such as 2N3906,....
-
You can easily build an infrared illuminator yourself at home with a little effort. You should have basic electronics knowledge on order to attempt this simple IR illuminator project. There is nothing difficult in this circuit. I have used 68Ohm and 1 Watt....
-
7809 is a voltage regulator integrated circuit(IC) which is widely used in electronic circuits. Voltage regulator circuit can be manually built using parts available in the market but it will take a lot of time to assemble those parts on a PCB. Secondly, the....
-
He artfully showed that within the quadrature concept, there must be three forces that can be manipulated and not just the two we have been working with [EM]. Electric field has Positiveand Negative voltage, Magnetic field has North and South poles,....
-
The air sampler is a highly effective multi-stage wetted-wall cyclone that continuously processes air at a 325 LPM rate, extracting particulates and transferring them to a liquid phase of 4 to 5 cc volume (see Figure 2). Distilled water is typically the....
-
A schematic representation of the SASS 2400 is shown in Figure 2 below. The cyclone has four main sections: a cyclonic cup, stripping column, cistern, and water feedback loop. A high-efficiency, brushless centrifugal blower at the cyclone exit pulls air into....
-
-
If you go to most supermarkets today you will see plug in mains powered digital programmable timers. These are designed to be used to automatically turn lights on and off, to turn washing machines on when you are out and so on. Prices start from as little as....
-
A Transistor is an electronic component which enables a small current to control a much larger current. This feature is very useful in many renewable energy projects and other applications. Click here to read our Introduction to Transistors. Pictured below....
-
A Float Switch is a device which is typically used to measure the depth/level of liquid in a container. As the water rises and reaches the level of the float switch, it begins to float going from the vertical to the horizontal. This closes an internal switch....
-
A dimmer for individual LED bulbs. LEDs (light emitting diodes) are very sensitive components - exceed their rated current or voltage and their lifespan can be slashed from 50, 000+ hours to an eventful microsecond. LEDs are current-driven * which means that....
-
-
A light/dark sensing circuit is extremely useful and versatile in a wide range of renewable energy projects from automatic lighting to security systems. In our article Light Dependent Resistor we explained how an LDR can be used in simple circuits to control....
-
A simple voltage status monitor built around the LM741 operational amplifier. These circuits are the best we have found in terms of accuracy, simplicity of operation, and cost. The LM741 is an operational amplifier. The wide range of uses of this simple and....
-
A Light Dependent Resistor (aka LDR, photoconductor, photoresistor, or photocell) is a component used commonly in electronics which has a resistance which decreases as the intensity of the light hitting its surface increases and visa versa. A typical light....
IC1 generates 150 µSec. pulses at about 80Hz frequency. Q1 acts as a buffer and Q2 inverts the polarity of the pulses and drives the Transformer. The amplitude of the output pulses is set by P1 and approximately displayed by the brightness of LED D1. D2....
The 8-lead plastic mini-DIP LM3909 IC was developed by National Semiconductor in the mid `seventies of the past century. It was a monolithic oscillator specifically designed to flash Light Emitting Diodes. By using the timing capacitor for voltage boost, it....
you could apply a step sequence that only triggers every other step, then, make the steps that do trigger, rise with each activation. From there you could apply that LFO to other parameters of the plugin to spice up the sound. (I. e. you could apply it to....
This controller is essentially 3 pairs of LED sensors in a 3G -bridge configuration. The driver is capable of operating 3 actuators. The motors are connected in a Delta configuration. The apexes of the delta are connected to the center connection of each....
This program includes circuit design cad, simulation, and auto routing PC layout. I also use PSPICE at Unisys which has more capabilities but costs 6 times as much and needs to be renewed yearly. With these requirements in mind, and some others, I decided on....
The above table is useful to determine the capabilities of the MOSFETs for the various versions. However, the connectors I have used on the LED3X "c" series is not rated for such high currents on a continuous basis. The connector is technically rated for 7....
The output level was set to 3. 8V peak to peak, not for any good reason, the first aim was to compare a few different op-amps before trying to further optimise the circuit. The op-amps were TL072, LM4562 and OPA2134. The distortion spectra are shown next, in....
It`s basically a standard Hartley oscillator, output is +7 dBm into 50 Ohms. Don`t be tempted to add a gate diode, this circuit doesn`t need it, and it will degrade the phase noise performance, according to Ulrich Rohde. It should be suitable for any....
To be used with PC connected to video projectors, where the lighting controller may require control of a presentation on the video screen but the PC for the presentation is located in a different location to lighting control. The Hardware required for this....
Connect a 12 volt 20 watt lamp and 12 volt battery to the circuit (observe battery polarity). Momentarily press and release the button to turn the lamp on. Repeatedly press the button to cycle through the power levels. Pressing and holding the button will....
This is a collection of various useful and interesting schematics. Some of these are also referenced by or included in other documents at this site. What isn`t here (this may not be everything): * Extremely important safety information. See the document: "....
The use of electrically excited gas discharges significantly predates the invention of the incandescent lamp. Physics labs of yesteryear as well as today have use of a variety of gas filled tubes used for numerous purposes involving light generation....
The high voltage power supply was probably good for 12 to 30 kVDC at 1 or 2 mA. This is useful for many high voltage experiments, plasma globes, negative ion and ozone generators, bug disintegrators, starters for really LARGE HeNe lasers, etc. The devices,....
This chapter provides detailed schematics of a variety of power supplies suitable for use with the common Ar/Kr ion tubes available to the hobbyist on the surplus market. Included are examples of commercial designs (Omnichrome 150R and 532 head, Lexel 88 and....
The carbon dioxide (CO2) laser is the powerhouse for high tech industrial cutting and welding of metals and many other materials. Small CO2 lasers are used for marking of metal, wood, and composites, and in medicine and surgery. Even a `small` CO2 laser....
The Pulsed Multiple Gas (PMG) laser described in this chapter is very similar in many ways to the Home-Built Pulsed Argon and/or Krypton (Ar/Kr) Ion Laser from Scientific American. However, the developers of the PMG laser have also used it with xenon (Xe)....
Many areas of scientific research and industrial production require vacuum conditions - where most (or as much as possible) of the air has been removed leaving little or nothing behind. While written specifically for the needs of home-built gas lasers, much....
This includes immunity to power line transients as well as those that may occur during power-on and power-off cycling. The parameters of many electronic components like ICs are rarely specified during periods of changing input power. Special laser diode....
This chapter provides a variety of circuits of both line powered and inverter types for the basic power supply, some with regulators, modulation inputs, and other goodies. Several have been reverse engineered from actual working commercial products. Some of....
This chapter contains circuit diagrams for several power supplies for pulsed solid state lasers. These include units suitable for driving the popular Hughes ruby and YAG rangefinder laser assemblies as well, one using the flash from a disposable pocket....
All of ACC`s repeater and remote base products support control of synthesized remote base transceivers. One form of frequency control supported is compatible with transceivers using thumbwheel frequency selection. The controllers supply BCD (binary coded....
Those of you who own large 500 watt and higher Astron linear power supplies, and even large HF amplifiers, know all too well that "GNNNNnng" sound that they often make when turned on. This is due to the high inrush (surge) current flowing into the....
This article provides conversion instructions for radio model # GE/MACOM MASTR-III Group 2 (150. 8-174 MHz) Repeater or Base, Combination Number SXS, to allow it to perform adequately in the 144-148 MHz range. Please be aware that this document is currently....
The artwork style of the opamp and of the meter face both suggest that is is an ACC design and is from an old issue of ACC Notes. I have credited it as such. I scanned the second image and wrote the text below from scratch. If anybody can locate the original....
This is a detailed explanation of a procedure you can use to modify a UHF MICOR "M" range (450-470 MHz) receiver board so it operates adequately in the 435-450 MHz range. This is an enhancement to Kevin`s text-only article. These receivers are commonly found....
Here are two photos of the interior of the NSN6054A. The two metal brackets that hold the circuit board in place also function as heat sinks for the 12 watt audio amplifier...
Many of us who use GTX 900 MHz radios to work amateur repeaters are well aware of the erratic output power problem. You go through the complete board replacement procedure, adjusting the deviation and output power, and everything looks great on the test....
This article describes one reliable, simple, and universal method of interfacing MaxTrac, Radius, and GM300 series of Motorola mobile radios to common repeater controllers. Most of this information also applies to radio interfaces that are used with IRLP or....
This page is oriented towards the USA marketed radios, simply because it was compiled by USA residents; we described the radios we are familiar with. If anyone would care to share information on the non-USA radios we`d be happy to add them on this page, or....
This article provides an overview of the R100 and MCR100 UHF repeaters. All of the information came from physical examination of the station and running the programming software, as well as the R100 Instruction (and service) Manual, p/n 6881078E15 and the....
No matter WHAT the label on the radio (or the seller) says, no Spectra will ever operate over the entire 136-174MHz (high band) or 403-512MHz (UHF) frequency range. Each unit will do only a portion of that band`s frequency spread, and that portion is called....
To build a GaAs FET preamp that has good gain and extremely low noise from readily available components. This preamp is stable with differing source and load situations. The circuit is built dead bug style on a piece of printed circuit board for a good....
This page deals with the subject of replacing the crystal in any type of Temperature Compensated Crystal Oscillator (TCXO), be it a Motorola "Channel Element", a GE "Integrated Circuit Oscillator Module" (commonly called an ICOM), or an RCA TCXO. Here we`re....
Another super-simple circuit. You could use this circuit to drive a low power speaker from a sound effects module or a noise generator. Or you could build your own amplified speakers for use with your computer. As shown (with no gain setting network between....
If your stereo amplifier does not have an input for a record player, you should use this circuit between your turntable and your amplifier. The output of your turntable follows a gain-bandwidth curve called the RIAA compensation curve. The standard AUX input....
This is a classic 2 transistor astable multivibrator. Many other NPN small signal or switching transistors can be used, including 2N4401, PN2222 or 2N2222 using the circuit on the left. The circuit can also be inverted using PNP transistors such as 2N3906,....
You can easily build an infrared illuminator yourself at home with a little effort. You should have basic electronics knowledge on order to attempt this simple IR illuminator project. There is nothing difficult in this circuit. I have used 68Ohm and 1 Watt....
7809 is a voltage regulator integrated circuit(IC) which is widely used in electronic circuits. Voltage regulator circuit can be manually built using parts available in the market but it will take a lot of time to assemble those parts on a PCB. Secondly, the....
He artfully showed that within the quadrature concept, there must be three forces that can be manipulated and not just the two we have been working with [EM]. Electric field has Positiveand Negative voltage, Magnetic field has North and South poles,....
The air sampler is a highly effective multi-stage wetted-wall cyclone that continuously processes air at a 325 LPM rate, extracting particulates and transferring them to a liquid phase of 4 to 5 cc volume (see Figure 2). Distilled water is typically the....
A schematic representation of the SASS 2400 is shown in Figure 2 below. The cyclone has four main sections: a cyclonic cup, stripping column, cistern, and water feedback loop. A high-efficiency, brushless centrifugal blower at the cyclone exit pulls air into....
If you go to most supermarkets today you will see plug in mains powered digital programmable timers. These are designed to be used to automatically turn lights on and off, to turn washing machines on when you are out and so on. Prices start from as little as....
A Transistor is an electronic component which enables a small current to control a much larger current. This feature is very useful in many renewable energy projects and other applications. Click here to read our Introduction to Transistors. Pictured below....
A Float Switch is a device which is typically used to measure the depth/level of liquid in a container. As the water rises and reaches the level of the float switch, it begins to float going from the vertical to the horizontal. This closes an internal switch....
A dimmer for individual LED bulbs. LEDs (light emitting diodes) are very sensitive components - exceed their rated current or voltage and their lifespan can be slashed from 50, 000+ hours to an eventful microsecond. LEDs are current-driven * which means that....
A light/dark sensing circuit is extremely useful and versatile in a wide range of renewable energy projects from automatic lighting to security systems. In our article Light Dependent Resistor we explained how an LDR can be used in simple circuits to control....
A simple voltage status monitor built around the LM741 operational amplifier. These circuits are the best we have found in terms of accuracy, simplicity of operation, and cost. The LM741 is an operational amplifier. The wide range of uses of this simple and....
A Light Dependent Resistor (aka LDR, photoconductor, photoresistor, or photocell) is a component used commonly in electronics which has a resistance which decreases as the intensity of the light hitting its surface increases and visa versa. A typical light....
