Free Simple Circuit Diagram
A LM3900 quad operational amplifier can be used to build a pulse width (PWM) controller. The LM3900 was chosen because it only need single supply voltage of 4 to 30 V. This circuit can give 100 percent pulse-width control. A1 op-amp forms a 1 kHz oscillator, generating a square wave oscillator for the basic oscillation. A2 is a ramp generator […]
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RS flip-flop, or reset-set flip flop, is a kind of stable multivibrator with two input, namely reset and set. The output will be at one of two stable states, set (active) or unset (inactive). A pulse strobe on set input will activate the output, and a strobe on reset input will deactivate the output. This two stable stage are provided […]
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This is a flash triggered (photo-driven) circuit which produce a pulse with constant predetermined wide. This circuit can be used to control any device which is required to be synchronized with optical trigger/flash light. The pulse can be used to drive relay (after proper power buffering, to drive other circuit logic, or electronic switch. We call it a pulse stretcher […]
Read moreOn these two following circuits, we can latch on the SCR (and thereby the lamp) by momentarily closing S1, thereby feeding gate drive to the SC via R1. The gate is tied to the cathode via R2 to improve circuit stability in both circuits. It can be turned off again after the SCR turns on only by temporarily reducing anode […]
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