Switching Circuits
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It is quite easy to miss the sound of a doorbell if you are watching TV, this circuit gets round the problem by providing a visual indication, i. e. a lamp. As an alternative, a LED could also be used. You could just parallel a lamp across the doorbell, but.... -
This simple device allows two computers to share a single USB printer or some other USB device, such as an external flash drive, memory card reader or scanner. A rotary switch selects the PC that you wish to use with the USB device, while two LEDs indicate.... -
This circuit switches a printer s USB connection from a PC to a laptop. What was needed was a method of allowing a laptop to use the printer occasionally while at all other times the printer would be connected to the PC. Instead of unplugging the printer.... -
The 555 is proved to be the most versatile and ubiquitous IC all over the world.This is a possible use: simple inverting schmitt trigger.... -
It sounds rather mysterious: a switch that is controlled by its ambient temperature. All without the touch of a human hand, except for when you re building this sort of electronic thermostat. There are a lot of handy uses for a thermally controlled switch..... -
This simple circuit will energize and de-energize a relay at the push of a button. Pushing the button once - will energize the relay. And pushing it a second time - will de-energize the relay. The accompanying Circuit offers a good introduction to the.... -
It is useful where the load needs to be switched on from one location and switched off from another. Any number of momentary (N/O) switches or push buttons can be connected in parallel.... -
A 100 second delayed turn ON relay RL1 switch, if plug power +12V in circuit. In Fig. 2 see a two range 6-60 second and 1-10 minute auto turn off relay timer circuit, with 555... -
A touch switch for a USB powered desk lamp, and the touch switch isn`t working. The circuit diagram, layout and pictures are below. I used the circuits from the following two websites to design the circuit: the 4th circuit. I`ve joined the output of the.... -
Ever wanted your home entertainment or sound system to power up itself when plugging in your iPod or other portable MP3 player? Watch this video to s.... -
This is a very easy instructable to build a digital switch for your camera in order to take photos with your microcontrollers. What you need: 1.... -
In order to switch some floodlights by my Arduino, the small switch circuits I built around a 39mf22 were just not man enough to handle the current ne.... -
This is a little circuit that i designed that could be used for achargingcontroller or voltage limiter. Its very useful if you are thinking of maki. In the assembly of the circuit u can alter the circuit as you please. For instance ididn`tgo as exact as.... -
Phase controlled AC voltage regulator, (a) Using back to back SCR and diode and (b) using inverse parallel SCR (c) Using diode-bridge and single SCR Figure 30. Input and output voltage waveforms for input 250V and output 300V. V1(V5): Input voltage- bottom.... -
if you are not getting anything at 66 RED then that is a problem. You could have your dash light dimmer turned to the "OFF" position. Or the corrosion on the wiper for the rheostat could be so bad it can`t make contact... -
There is only one circuit breaker (no fuses) for the system. If you can follow the schematic, it shows that the switches are used to supply Power (12 volts) and Groundto the window motors in opposite polarities to make the windows go up and down. So we will.... -
A 1984 F-350 crew cab w/a 460. My fuel gage does not work and it will not pump from the front tank, were do I start I have replaced the switch in the dash and the switch on the frame. I just turned it on and did not hear anything. The pigtail that goes into.... -
New applications for DC voltage converters, such as the workhorse` LT1070, arise every day. These converters can be adapted to nearly every imaginable ratio of input and output voltages. However, all of these circuits and devices have the same shortcoming,.... -
This circuit can switch two or more devices on and off in response to a series of rapid handclaps. The claps are picked up by an electret microphone and amplified by a 741 op amp (IC1). IC1 is configured as an inverting amplifier, with its gain and hence the.... -
Mechanical contacts have the disadvantage that they wear out. That is why it is practical to use an electronic touch switch` in some situations. With such a touch switch the resistance of the human skin is used for the switching action. The schematic shows.... -
In most countries it is now mandatory or at least recommended to have a rear fog light on a trailer with the additional requirement that, when the trailer is coupled to the car, the rear fog light of the towing car has to be off. The circuit shown here is.... -
In these times with viruses and other threats from the Internet it would be nice to have reassurance that the PC cannot be infected. That is why this circuit was designed. It makes it possible to install multiple hard disks inside the case of a PC, which are.... -
Turn ON or OFF electrical devices using remote control is not a new idea and you can find so many different devices doing that very well. For realization of this type of device, you must make a receiver, a transmitter and understand their way of.... -
This circuit allows a 240V mains appliance to be controlled remotely via low-voltage cabling and a pushbutton switch. The mains appliance (in this case, a light bulb) is switched with a suitably-rated relay. All of the electronics is housed in an ABS box.... -
In this age of enlightenment any sort of relationship that could be described as master/slave would be questionable but for the purposes of this circuit it gives a good idea of how it functions. The circuit senses mains current supplied to a master` device.... -
It is sometimes necessary for an RC (remote control) model to contain some kind of switching functionality. Some things that come to mind are lights on a model boat, or the folding away of the undercarriage of an aeroplane, etc. A standard solution employs a.... -
As the only electronics engineer in my family and circle of friends, it is sometimes not possible to evade an appeal for help. This time the request came from a friendly elderly lady in a retirement home. In her room the light switch by the door and the pull.... -
This circuit switches a printer`s USB connection from a PC to a laptop. What was needed was a method of allowing a laptop to use the printer occasionally while at all other times the printer would be connected to the PC. Instead of unplugging the printer.... -
We used as a starting point for our experiments, the switching device John Bedini had built for the Tesls Symposium. Our goal was to upgrade this switching device for ordinary car or motorcycle batteries....
New Circuits
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This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of.... -
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is.... -
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to.... -
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This.... -
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the.... -
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,.... -
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the.... -
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power.... -
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
Popular Circuits
This circuit, connected to 32 Ohm impedance mini-earphones, can detect very remote sounds. Useful...
This indicator is basically a switch with hysteresis characteristics. If the input voltage...
30W Class AB power amplifier circuit diagram using power transistor. Set the above amplifier up...
To operate a small motor used for opening and closing a pair of curtains. DC motor has six basic...
Figure A is the schematic of the microstrip single stage RF amplifier. The amplifier is based on...
This is an UHF band TV antenna preamp circuit with 15dB gain and build by a transistor. It is...
This circuit uses a small AC current transformer from Magnetek to produce an isolated voltage...
This metal detector schematic circuit is based on a transistor radio as an detector .This metal...
A 1999 Pontiac Montana. The information console that shows temperature, MPG, compass, etc. failed...
By an integrated power amplifier TDA2040 (lC) can also form OCL power amplifier (OCL meaning is...