Free electronic circuit design and schematic diagram
This is an oscillator circuit that can be used for calibrating frequency counters, amateur receivers and frequency meters. This circuit is called 2MHz standard with dividers circuit. This circuit uses two crystals, 100kHz and 2 MHz. Here is the schematic diagram of the oscillator part of the circuit: This circuit is then can be combined with two 7490 decade counter […]
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Monitoring battery voltage can be important in some application. Some battery monitor will be simply a continuous LED lamp which is dimming according to the voltage level. Here is presented monitoring circuit that flashing, which is more noticeable than simple dimming the light intensity. At 1.2V, the LED begin flashing, and the flashing rate will increase as the voltage increase. […]
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The circuit of off-air monitor for SSB transmitter can be built by using combination of detector product with the crystal oscillator. This circuit is used for testing the audio at one point within band. The quality of audio will still constant, if loading and tuning of SSB transmitter are same over rest of band. The LC circuit will resonated to […]
Read moreBelow is video tutorial about automotive ignition coil. The coil is composed of primary and secondary circuit. The primary circuit is consist of two terminals. It’s connected to the steady 12 volts battery and ignition module or ECM. The secondary circuit is connected to the spark and carry a high voltage. The ECM module will always looks for returning voltages […]
Read moreThis is a intake air temperature (IAT) sensor video. This video shows how the IAT sensor works. This sensor has two terminal, the ground terminal and reference voltage terminal. The ground is connected to the pin 5 of OBD-2 and the 5V refence signal is supplied by ECM. This sensor is maybe located in intake air deck. Here is the […]
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Remote sensor might cause a trouble if it’s a passive type, has very low power output, and should be connected with relatively long cables. By supplying a current or voltage source through its connection wire, it’s possible to make long enough wiring without suffering much noise/interference. The following schematic diagram show a circuit consist of LM10 to make a remote […]
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A low-loss way to implement a”glitch-free” battery backup for a memory or similar circuit is shown on the following schematic diagram. To make LT1020 does not conduct under line-powered conditions, we have to arrange the feedback string. The line LT1020 begins to go off when the lie goes down, which allows the battery-driven LT1020 to turn on and maintain the […]
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