MOSFET Amplifier IRFP240/IRFP9240

[djk]

It means that people forget this so many times that he should add it to every post he makes.

(my signature line is: Candidates for the Darwin Award should not read this author. )

 

[wattaniya]

hi apex sir,
now i connect input gnd to psu gnd.
now dc offset showing 105mv. is this ok?
the 15zdiodes reading one is showing 6.6vdc other one 3.3vdc any my mistakes,
the 10ohm 10watt resistor is getting little heat.
what i have to make changes.

 

[wattaniya]

hi apex sir,
finally the sound is come out, very clear sound and no on off thumb.
thanks sir.

 

[HighTec]

It means that people forget this so many times that he should add it to every post he makes.

(my signature line is: Candidates for the Darwin Award should not read this author. )

Speaking of which, is there a Darwin's Award for the candidates in electronics?

 

[djk]

I almost earned it when I was in high school.

I removed a big capacitor in the high voltage section of an oscilloscope (without discharging it first). It bit me so hard my arm contracted and threw the cap across the room. I was so stupid I went over, picked it up, and got bit again!

I now work with MUCH higher voltages. No one is allowed to come near me, or to even talk to me, while I am doing a high voltage test.

 

[wattaniya]

apex sir,
i supply 70vdc, and the dc offset is showing 145mv dc.
i connect input gnd to psu gnd.
what will be the problem?
little sound is coming out with low volume (volume control i turned to ccw 0 level but little sound is coming through speaker)

 

[wattaniya]

apex sir,
can u check 486 post.

 

[apexaudio]

apex sir,
i supply 70vdc, and the dc offset is showing 145mv dc.
i connect input gnd to psu gnd.
what will be the problem?
little sound is coming out with low volume (volume control i turned to ccw 0 level but little sound is coming through speaker)

Match input transistors to get under 30mV dc offset. 145mV dc offset and little sound on 0 level is not big problem.
Regards

 

[wattaniya]

Simple Soft-start, DC, Thermal and Overload Protect with NE555. Use single 12vac for suply.

hi apex sir,
the protection board in progress.
is this protection suitable for h900?

 

[apexaudio]

hi apex sir,
the protection board in progress.
is this protection suitable for h900?

No, PRO pins are not compatible on H900 and HV23, but if you don't want use overload protect you can use this protect with any amp.

 

[wattaniya]

thanks sir for the quick reply.

 

[QQ12e5k1]

No, PRO pins are not compatible on H900 and HV23, but if you don't want use overload protect you can use this protect with any amp.

I've built your HV 350 PSU,can I use it for B500??
Does it protector will working good??

Regards

 

[apexaudio]

I've built your HV 350 PSU,can I use it for B500??
Does it protector will working good??

Regards

Yes, but without overload protect,
Regards

 

[wattaniya]

hi apex sir,
i finished and tested this protect, but not working,
what will be the problem?

 

[apexaudio]

hi apex sir,
i finished and tested this protect, but not working,
what will be the problem?

Protect can't work without 10k NTC (thermal protect), but you can use 10k resistor instead NTC for test.
Regards

 

[wattaniya]

Protect can't work without 10k NTC (thermal protect), but you can use 10k resistor instead NTC for test.
Regards

thanks sir for the reply.
ok i will buy 10k ntc and check.

 

[wattaniya]

hi apex sir,
now i put 10k ntc .
now the protect circuit is working, but when power on , the relay delay time is one second ,because the led indicator only blinking once and after relay connects the led permanently lights on, how can i increase the delay time to 3 or 5 seconds?

 

[aman khalsa]

hi apex sir,
i finished and tested this protect, but not working,
what will be the problem?

hello sir ..can u pls share pcb lay out and digram..???. thank u...

 

[wattaniya]

hi khalsa check post no 475.

 

[wattaniya]

hi apex sir,
now i put 10k ntc .
now the protect circuit is working, but when power on , the relay delay time is one second ,because the led indicator only blinking once and after relay connects the led permanently lights on, how can i increase the delay time to 3 or 5 seconds?