Hi,
Here is the schematic if a 12V electric fence energiser that I have but is not working anymore (corrosion damage)
I hope I drew the circuit right. I think I understand most of it but I wouldn't mind someone else's input.
Basically it is an Armstrong oscillator (similar to the popular joule thief), charging C4 and C5. At the same time, C6 get charged (by voltage spikes when T1 cuts off? ) When voltage in C6 gets high enough, it triggers SCR1 (and discharges through SCR1 gate?)
That discharges C4 and C5 through the output transformer, giving the pulse for the fence and flashes the neon indicator beside R3.
R3 and R4 are simply a voltage divider to supply the neon bulb with the right voltage (C3 disable C4 and C5 from discharging through R3 and R4? )
I guess D3 is there to protect T1's base from reverse polarity spikes.
Are P1 and P2 there to set the duty cycle?
Is P1 setting the space and P2 the mark? (P1 setting how fast C1 charges thus how long it takes for the base voltage to get high enough. And P2 sets the base current,thus how fast C1 discharges. Or is it doing something else?)
Probably got the part wrong.
C2 selects the frequency of the pulse. Is it simply lowering the frequency of the oscillator, thus taking longer to charge the C4 C5 capacitors?
I don't really get the role of D2 and D4.
What did I get wrong, or miss?
Thanks
Ben