IC 7912 and resistor 47R/5W are used for fan suply... post pictures with botom side of your pcb.
hi sir apex can I use a tranformer with 45-45-0-45-45 VAC with 4 pairs of output transistor in this type of clas h-amp? I tried this h-amp using 30-30-0-30-30 VAC with out problem and sounds great to my ears so I want it for more power.
Thanks in advance
This image is not updated, only the addition of paths in the relay coil to the diode
diyAudio
http://www.diyaudio.com/forums/atta...6308-900w-h-class-pa-amp-limiter-img_0371.jpg
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i was commenting from bus on my way home and did not have schematics to see so i thought that it supplies the relay coil. anyway,power disipated by 5W resistor and voltage regulator is to be calculated as i said and than decide will you replace the resistor and put the heatsink od voltage regulator,wich i would anyway. greetings!
OK, thanks for the advice. I hope Mr. APEX can provide input for this. problems in R 5 Watt and IC 7912 are very hot.
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Replace IC 7912, without fan connected to pcb IC and 5W resistor must be cold. With connected fan only resistor 47R/5W can be warm.
I have yet to install the fan into the relay module test only can work or not, after I check the IC 7912 and R 5 Watt hot, with no load (Fan)
Please see attach picture!
Attachments
Post #2305 shown it's been rectified.... now he has heat issue with 47R/5W and IC 7912.
Damanhuri, My protect it only get warm this two component having the fan connected, if the fan is disconnected they must be cold.
Regards,
Hello Mile sir,
Having built B500 I m impressed by the performance of the amp. The next step is to get the most juice out of my 2.5kva toroid and 2kw speakers.. I have gone through this thread and finally decided to built H900. What I couldn't find is H900 schematic with 8pairs of output transistors to support 2ohms and 16 ohm loads. Maybe I have missed it. So I am looking for H900 triple emitter follower schematic/circuit . I request Mile sir or diy members to please help me with H900 tef circuit. Thank you
Having built B500 I m impressed by the performance of the amp. The next step is to get the most juice out of my 2.5kva toroid and 2kw speakers.. I have gone through this thread and finally decided to built H900. What I couldn't find is H900 schematic with 8pairs of output transistors to support 2ohms and 16 ohm loads. Maybe I have missed it. So I am looking for H900 triple emitter follower schematic/circuit . I request Mile sir or diy members to please help me with H900 tef circuit. Thank you
Thanks for reply. Damanhuri, pls check the reisistance of your IC7912 and 47R/5W.
Happy holliday to all...
This forum is verry helpfull. Specially thanks to mr mille...
Your dsign is unic n naturally but expert....
good job sir...
Nice..
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Thanks,
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