Post #537: +/-45V, do you reed it? I suggest to use for +/-MV half of +/-HV, and you can use same all caps in series for PSU.
Regards
You are wrong +/-MV connect to +/-MV not to +/-OVD. That is simple and clear I hope.
Regards
ok I hope this will be fine now.
the PSU is here...
An externally hosted image should be here but it was not working when we last tested it.
the PSU is here...
An externally hosted image should be here but it was not working when we last tested it.
Add step driver with TL072 to B500, you can use PSU from H900, and you get class H amp with same power as H900.
Yes, you have some wrong notification ( 33pF ), and why you don't try to design PCB with both circuits on it? Something like DJ.DUMY in thread:
http://www.diyaudio.com/forums/solid-state/162408-900w-h-class-pa-amp-limiter-44.html#post2165701
post #435
Regards
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thanks Apex 🙂 it should be 100N. I will try to incorporate the step driver to B500 PCB.
so i will use 4x40 volts ac ... how about the tx capacity? do I reduce it?
BTW: thanks for the explanation about your Protect circuit. I check it tomorrow.
so i will use 4x40 volts ac ... how about the tx capacity? do I reduce it?
BTW: thanks for the explanation about your Protect circuit. I check it tomorrow.
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I use 1800VA transformer for stereo H900, put in 2U case with two fans. Add VI limiter, then it can be use with any protection, as I can see many diyers do not like to use protection, but B500 and H900 must be use with my original protection for PA. Fuses is not enough, but with add VI limiter will work.
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Wow! I will have a B500 Class H... thats nice. I will do the same layout as yours since it is easy to fix in heatsink.
your right apex... H900 🙂
what single op-amp you can recommend with the same specs of tl02?
what single op-amp you can recommend with the same specs of tl02?
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Hi Apex,
what is the condition of fan in the protect circuit at low temp? is it running at slow speed and when the temperature reach 60 degress it will run at max speed?
tnx,
coolet
what is the condition of fan in the protect circuit at low temp? is it running at slow speed and when the temperature reach 60 degress it will run at max speed?
tnx,
coolet
Fan run at low speed (12V), and full speed (24V) over 60 deg. If you drop resistor 47R/5W fun will run only at full speed when the temperature is over 60 deg.
Regards
Most PA amplifiers have DC protect with TRIAC, it's trigger at 33V DC across DIAC and tiac shorted speakers output. Dynacord use both protect (triac and relay) on P3000. 5V DC for trigger protect will be OK.
Regards
using a low pass filter on the amp output generates a delay.
At very high DC offset voltages the delay is quite low and the detector can trigger in less than 40ms, a really fast circuit might get to less than 20ms.
At lower output offset, the filter has the effect of delaying detection.
This can extend the delay time of the trigger to ten times say, half a second for a DC offset of ~2V.
I would suggest you aim for a very fast detection of rail voltage offset and allow a much longer delay before protecting for lower offsets.
This same filtering at the output also reduces the circuits detection of pluses and minuses in the alternate waveforms. A very fast detector of near rail to rail AC output would continuously detect and trigger on full voltage output audio signals.
The filter attenuates the AC so that only very low frequencies will be detected.
One can easily get a circuit that will pass full output voltage 20Hz signals and detect and trigger within 40ms of a full voltage DC offset. Passing 10Hz @ full voltage and detecting and triggering a DC offset in <20ms would be quite a bit more difficult to achieve.
At very high DC offset voltages the delay is quite low and the detector can trigger in less than 40ms, a really fast circuit might get to less than 20ms.
At lower output offset, the filter has the effect of delaying detection.
This can extend the delay time of the trigger to ten times say, half a second for a DC offset of ~2V.
I would suggest you aim for a very fast detection of rail voltage offset and allow a much longer delay before protecting for lower offsets.
This same filtering at the output also reduces the circuits detection of pluses and minuses in the alternate waveforms. A very fast detector of near rail to rail AC output would continuously detect and trigger on full voltage output audio signals.
The filter attenuates the AC so that only very low frequencies will be detected.
One can easily get a circuit that will pass full output voltage 20Hz signals and detect and trigger within 40ms of a full voltage DC offset. Passing 10Hz @ full voltage and detecting and triggering a DC offset in <20ms would be quite a bit more difficult to achieve.
that was a nice exlpanation andrew. i was hoping to make a microcontroller controlled protect circuit from apex circuit. so far apex give me informations how the circuit work. my main concern is, does the microcontroller make a noise interference to the amplifier? it would run at 4mhz internal oscillator.