Jagau
posted this
09 March 2023
Excellent Replication Alteredunity, bravo
By any chance are you able to describe the operation of maybe this circuit
The purpose of this circuit is to make lit the LED D3 in the small yellow square. The red square represents the supply of the circuit, the ambient AC is rectified in DC tension and stored in C2
The entire green square represents the switch which is closed only when the voltage divider R1 and R2 reaches the desired tension of activation of the SCR Q1 and Q2. The resistors are very high in order to have a minimum current in the voltage divider.
In the following image the two ways to have a SCR operated with two BJT, positive pulse and negative way for momentary pulsed activated by the capacitor C1 and R4 .
Yes, the Q1et Q2 transistors, in the greater yellow square, are configured as a switch, SCR well known like the SRO, which is triggered by the C1 R4 and Q3 arrangements, in the brown square, configured to activate the PNP which requires pulse to close the SCR Q1 and Q2 and thus lit the white LED.
In a short way, C1 R4 activates Q3 which sends a positive pulse to the base of the SCR Q1-Q2 which puts it in conduction mode and lights the LED and the cycle begins again.
The easiest explanation possible, I hope you understood correctly ?
Jagau