Hi, SilvioI cannot see why the circuit does not work with the IRS chip. They suppose to have the same structure as the dip types. Regarding the led its rather difficult really as during operation the aux winding is supplying the voltage and when the SCR fires it pulls the supply to ground. Adding any resistance here may not ground the supply rail in time. As the chip stop oscillating only the start up circuit is in operation but this will only supply a few milliamps and may not be enough to light up the led.
Regarding some more modifications. Well I hope ZD1 is around 150v. To aid start up you can chainge ZD2 to 12v, ZD3 to 15v and change R8 to 120R. Before making changes check the input voltage before R8, this should be 17v to 20v. Check voltage at pin 1 this should read 13v. With the chip removed the startup voltage at pin 1 should not be less than 10v. I encountered some chips that need 11v at start up and refuse to start at a lower voltage. It could be that fake chips draw more current at start up.
Hi again Benny, the high frequency startup is because the IR2153 does not have a soft start. Charging the secondary capacitors at startup present a nearly dead short especially if having more than 2000uf on each of the center tap windings. However starting the trafo with 3 times the frequency cannot deliver that much current as this is wound for a lower frequency. This will reduce the stress on the mosfets and prevent them from burning.Hi, Silvio
I recently got some more IR"S"2153 again.
I am under the current configuration of IR2153
Some ICs can work, some burn up when they go up, and they are not stable.
I re-read the datasheet of IR"S"2153
It seems that the working frequency is not as high as IR2153(IR"S"2153 is limited up to 100k)
I suspect that the IC may be burnt under 3x frequency startup
*In addition, what are the advantages of 3 times the starting frequency? And why?
Maybe it can be started at normal frequency and it can work well(about 50~70k)
Thanks & Regards
All seems well. Just one small detail. The primary snubber capacitor usually has a pitch of 7.5- 10mm (ceramic type 1 or 2kv) and the snubber resistor is usually is of the 3watt type. Make sure that these will fit. I cannot determine the pitch used but assuming by proportion. As for the secondary snubber these are usually of a lower wattage but still use a ceramic type.Control board V1.2:
SMPS board V1.3:
I see no output for a fan motor which normally is essential in an amplifier. This will also help if needing a separate 12-15v dc for the speaker protection relay. Ideally this part does not share a common ground with the preamp stage.Control board V1.2:
SMPS board V1.3: