Checker Circuits |
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This circuit runs a fast battery test without the need of power supply or expensive moving-coil voltmeters. It features two ranges: when SW1 is set as shown in the circuit diagram, the device can test 3V to 15V batteries. When SW1 is switched to the other position, only 1. 5V cells can be tested. FET Q1 provides a constant current generator biasing .
Everybody who regularly works with servos will know several instances when such a servo tester will come in handy. The function of a servo tester is to generate a pulsing signal where the width of the positive pulse can be varied between 1 and 2 ms. This pulse-width determines the position the servo should move to. The signal has to repeat... .
This circuit came from a need for a quick and dirty network tester that could be operated by one person. All the commercial units I tried required a person at the other end to check the remote LEDs, as the transmitters could not be made to cycle through the test continuously to allow one person to check both ends. It must be noted that this uni .
Designing a true constant-current AA NiMH charger, and want to select a power supply that will be just right. I want a high enough voltage to that the CC transistor doesn`t saturate, yet low enough voltage to reduce the power dissipation in the transistor. I plan to build a unit that will charge two seperate banks of 2 NiMH cells in series at0.... .
Here is a handy gadget for test- ing of infrared (IR) based re- mote control transmitters used for TVs and VCRs etc. The IR signals from a remote control transmitter are sensed by the IR sensor module in the tester and its output at pin 2 goes low. This in turn switches on transistor T1 and causes LED1 to blink. At the same time, the buzzer beeps .
The first timer IC555 creates a negative trigger signal of approximately 45Hz (a trigger impulse every 22ms, DO NOT exceed 50Hz for proper servo function). The second timer IC555 modulates a positive square signal from 0. 9ms to 2. 1ms every 22ms, a method commonly known as pulse width modulation (PWM). The modulated pulse width provides the... .
Although you don`t find SCR and Triac in all electronic equipment, this does not mean that both are not important components. You need to learn how to test it so that when you come across one in the future you will know if it is good or bad during troubleshooting. You can test these components using meters but with the SCR/Triac tester you will fi .
FETs can be found in the power section, LCD inverter, UPS, Amplifier, Monitor B+ and S-correction circuit, ATX power supplies and etc. When this component fails, one has to use a meter to test it to check if it is good, shorted, openor leaky. The meters can be a normal multimeter, specialize FET tester like the Peak Atlas Tester, Sencore Cricket... .
This small InfraRed Remote Control Tester circuit is used for checking the operation of an infrared remote control unit. The circuit is based on the idea of connecting a piezo buzzer directly to an IR receiver IC. The TSOP1738 integrated IR receiver accepts, amplifies and demodulates the IR signal from the remote control, producing an output with .
This is a multifunction RJ45 network cable tester. It is the design of the network cable (RJ45) test, and telephone (RJ11). It is cheap and easy to use. It works for network, telephone, cable with RJ45 half Registered Jack plug immediately indicate whether a crossover network cable or straight, flashing a yellow or green LED. If something is br .
The idea for this crystal tester circuit sprung out of the need of testing a large number of oscillator crystals lying unused in a big hobby box. testing the crystals one by one without the appropriate device would have been very slow and a time consuming task. Commercial crystal testers are however very expensive, that is why this simple electron .
This circuit uses the popular and easy to find LM3914 IC. This IC is very simple to drive, needs no voltage regulators (it has a built in voltage regulator) and can be powered from almost every source. When the test button is pressed, the Car battery voltage is feed into a high impedance voltage divider. His purpose is to divide 12V to 1, 25V (or l .
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