Hello all.
After retrieving my Dataman S4 which was last used about 6 months ago I found it dead. Hence I am in the process of reverse engineering the PCB.
The image is a snippet of my circuit and shows the first stage power supply. 15VAC comes in, gets rectified and then... meets a strange SCR based circuit.
What I know about SCRs one could write on the back of a postage stamp. At a WILD guess I think this some kind of elaborate regulator (at 8V?).
I wonder if there are any one here that can explain this circuit please. I wonder why the original designer plopped for such a whacky design instead of using a standard design.
Regards & thanks in advance, A
After retrieving my Dataman S4 which was last used about 6 months ago I found it dead. Hence I am in the process of reverse engineering the PCB.
The image is a snippet of my circuit and shows the first stage power supply. 15VAC comes in, gets rectified and then... meets a strange SCR based circuit.
What I know about SCRs one could write on the back of a postage stamp. At a WILD guess I think this some kind of elaborate regulator (at 8V?).
I wonder if there are any one here that can explain this circuit please. I wonder why the original designer plopped for such a whacky design instead of using a standard design.
Regards & thanks in advance, A
The circuit is a battery charger. The SCR triggers on every half cycle when the battery voltage is low. I think that D6 should be a zener.
An SCR is being used because it is efficient (switching).
Ed
An SCR is being used because it is efficient (switching).
Ed
The transistor is there to turn the SCR (charger) off when the fully charged terminal voltage is reached. Crude but operable.