Analog PWM Circuit

[KyleCarrington]

Very interesting! With no center tap on the primary, is the current filling caps, then discharging, then filling caps... back and forth to create the (approximated) AC necessary for the transformer to step up or down... What is the output on the secondary is it square wave AC, triangular wave?

[geekjoan]

Stills can be put on some other place than youtube...

[lhgrubbs]

Connect one leg of the 50K ohm pot to the output side of the cap from T2.

[oleglyan]

T=ln2(RC_1+RC_2)

[newbeatlee]

hi , i see that in your circuit you shown a 47k? resistor that goes from ground to the middle pin of a pot (the values is not so clear) . where it suppose that goes the other 2 pins of this pot ? thanks

[lhgrubbs]

@newbeatlee It is a 50K variable resistor listed in the Parts list

[newbeatlee]

ok but how oe where you connect this pot ?

[joshrozich]

Wheres the part list

[lhgrubbs]

2 x 1K resistor 2 x 4.7k resistor 2 x NPN Transistors 1 x 50K variable resistor 1 x 22K Resistor 1 x 47K Resistor 1 x 22uf coupling capacitor 1 x .05uf 1 x .1uf 1 x pnp transistor 1 x medium size 10x transformer 12vdc utility powersupply Sincerely LeRoy Grubbs

[anven11]

Thanks for that:D