Re: Help..problem with test circuit of SG3524 duty ratio..
After I put the base-emittor resistor, there appeared a pulse on pin 12 and 13,when they are not shorted together, both of duty ratio 0.5. But the duty ratio do not changes if the voltage at pin 2 is changed. The voltage at pin 1 is 0, since the output voltage is 0.
I can see pulse of 0.5 duty ratio on the base of PNP BJT, which oscillates between 2 V to 20 V. The voltage at emittor of the PNP BJT is continously 20 Volts. Still the voltage at the collector never increases. What keeps it always low.?