i bought a kit from sure electronics it worked well....then i thought to take the voltage readings so that i can make sureness when i build my own one if it is correct or not.....i took all the readings but when i went to take the reading of vcc mistakenly the probe touched to VS pin but dint short to vcc and the amp turned dead....i tested this thing on one side of the board but the other side also was off after that dont understand why is it so.....
NEED HELP,,,,,any feedback would be highly appreciated
NEED HELP,,,,,any feedback would be highly appreciated
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one thing for sure the probes were not shorted....and i found that on ref kit the bias voltages of both channels are joint thru a jumper....and was not knowing that ...made me blow another fet.....how much RMS output can be pushed out from IRFI4019
I found the 2092 to be very touchy about scope probes.
I touched a single pin and blew it up.
If you want to monitor voltages switch the amp off first. Let PSU discharge then connect your probe securely then turn on.
I use a 150r resistor on a croc clip to discharge the supply caps completely.
I also blew up a couple of 2092's by inserting them with undischarged supply capacitors.
I would check the mosfets too as they sometimes go with the 2092.
I have had numerous D-S shorts but also once got a G-S short.
I touched a single pin and blew it up.
If you want to monitor voltages switch the amp off first. Let PSU discharge then connect your probe securely then turn on.
I use a 150r resistor on a croc clip to discharge the supply caps completely.
I also blew up a couple of 2092's by inserting them with undischarged supply capacitors.
I would check the mosfets too as they sometimes go with the 2092.
I have had numerous D-S shorts but also once got a G-S short.
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Nigel
Thanks nigel...i think I got it...whatever I need to do with attachment of probes is while the supply is off and the caps are fully discharged...can I monitor the hi and lo voltages with same manner....and can the OCP works well if gates are buffered and output is lets say 1000watts will OCP work very well as it does with low voltages and output without damaging the IC???....and buddy I also have 100's of fets damaged in that manner
Thanks nigel...i think I got it...whatever I need to do with attachment of probes is while the supply is off and the caps are fully discharged...can I monitor the hi and lo voltages with same manner....and can the OCP works well if gates are buffered and output is lets say 1000watts will OCP work very well as it does with low voltages and output without damaging the IC???....and buddy I also have 100's of fets damaged in that manner
Nigel
Thanks nigel...i think I got it...whatever I need to do with attachment of probes is while the supply is off and the caps are fully discharged...can I monitor the hi and lo voltages with same manner....and can the OCP works well if gates are buffered and output is lets say 1000watts will OCP work very well as it does with low voltages and output without damaging the IC???....and buddy I also have 100's of fets damaged in that manner
Yes you can look at HI and LO outputs using that method.
I found I had to scale back the OCP threshold to stop the amp cuting out on high power.
Buffering the gates will speed up switch on of mosfets and stop OCP being so sensitive to slow edges.
Buffering the gates will allow driving more mosfets or more capacitive gate mosfets. The gate buffering takes the load off the 2092.
I use TC4420's for gate buffering.
You might find you have a problem with turn off thumps or siren type power down noises when the power supply gets really big. If you can live with that then fine but I couldnt and added a small PIC based circuit to detect low VCC and then turn off CSD using an opto coupler. I used to be a PIC consultant so use them a lot but you migh tget away with a comparator and opto coupler. I also found I couldnt drive CSD direct from the opto-coupler, I had to use a 390r is series with it to stop blowing up the 2092.
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thanks .....it was a great information for me....what do u think how much pairs should i use for getting 1000watts @ 4ohms load with what voltage......i'm getting too humbled as i'm unable to find IRFB4227 around anywhere......can u suggest any other mosfets which i can use for the amp!!!!!!
63volts will give 100watts????????????????//.....buddy i need to know about 1000watts
I basically used the 2092 datasheet circuit but added mosfet gate drivers.
The VCC capacitor is 100uf. The high side power supply has 47uf.
I also scaled down the voltages into the over current pins to stop resetting on high power. Decouple the mosfets very close to them. Decouple the 2092 very close to the IC.
An externally hosted image should be here but it was not working when we last tested it.
thanks.....if i use 4 pairs of irfb4020 at 70volts can it be used @ 4OHMS load???? and what output power can it deliver?????????
nigel plz refer to IRFB4020 datasheet....it says it can deliver 300watts @ 8OHMS then if i use 4pairs then can i use it for 4ohms.....its dual package is IRFI4020 which is used in 2092's ref designs in which it says that 4ohms is not supported!!!!!!!!!!!
THANKS ALOT,
these are cheap ones and i can get i very easily.....i likd the irs2092's OCP protection....does it work same as it does on low outputs if i drive it for 1000watts then if there is short on output will it bear it or just give me a haunting smoke out of it??????????/
The OCP will work the same.
Its a matter of juggling the trip voltages so they dont trip during normal use but do if there is a short.
You can work out trip voltage by using the mosfets D-S on resistance times the max current draw.
I found it wasnt very reliable and just upped the trip voltage until it stopped resetting on full power.
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