What this 555 circuit

Thread Starter

jafal

Joined Jul 4, 2017
31
Hi all

The ic is 555 timer generate maximum 1 khz square wave
The diode is 1n4148
The combination of the Dodie rlc what and how works

Thanks in advance
Screenshot_2023-03-21-09-30-29-425.jpeg
 
Last edited by a moderator:

Reloadron

Joined Jan 15, 2015
7,501
The diode and 1K resistor look to be configured as flyback for the coil. Unless the diode anode goes more positive than the cathode the diode will never be forward biased. What exactly is the coil? The inductor (coil) and capacitor form a series LC circuit. The coil inductance is unknown? If the cap were not in series with the coil and the transistor was maybe an old 2N3055 I would have guessed an ignition coil test circuit but the cap is in there forming a series LC circuit.

Ron
 

Thread Starter

jafal

Joined Jul 4, 2017
31
The diode and 1K resistor look to be configured as flyback for the coil. Unless the diode anode goes more positive than the cathode the diode will never be forward biased. What exactly is the coil? The inductor (coil) and capacitor form a series LC circuit. The coil inductance is unknown? If the cap were not in series with the coil and the transistor was maybe an old 2N3055 I would have guessed an ignition coil test circuit but the cap is in there forming a series LC circuit.

Ron
Hi

Thanks for your response the transistor 2n 3904

And the coil is not critical value
 

Attachments

Reloadron

Joined Jan 15, 2015
7,501
Hi

Thanks for your response the transistor 2n 3904

And the coil is not critical value
Well then the 2n3904 is a common switching NPN transistor with a max current of about 200 mA if I recall correctly. The 103 labeled is a ceramic disk of 10,000 pF. I don't see where the 1N4148 will ever be forward biased? Less knowing the inductor value I am not sure what the circuit is supposed to do. :(

Ron
 

Thread Starter

jafal

Joined Jul 4, 2017
31
If you don't know what the circuit is, what it does, or how it works, how do you know that the value of the coil isn't critical?
I am asking to get knowledge not get evaluation from you

I know that the coil is not critical because I saw the circuit many times and each time the coil vary in length it was much more useful if you explained about the circuit rather than evaluate people
 

Thread Starter

jafal

Joined Jul 4, 2017
31
Where does the circuit shown connect to the laser diode semiconductor section terminals?
I don't know where the laser diode terminal's connected It is 5 volt laser diode but i think one with positive terminal of the coil on main dc line and the other to the transistor emitter terminal I think the circuit change the current of the laser diode or making sort of modulation
 

BobTPH

Joined Jun 5, 2013
8,804
Somehow, I doubt that the circuit is correct as drawn. There is no DC path through the transistor. But then we don’t know where the laser diode is connected.
 
Top