Makes me cry... it's such a mess!
EPC- truely a Pzgouraz engineering marvel
A picture showes more than ...
It is actually a microcontroller operated PWM controller. The board with the leds is where the throttle is wired to, it`s purpose is to generate the pwm.
Thats the only thing the 8 pins Atmel does here. The leds dont have any purpose, the board is cannibalized from some chinese toy.
The black cube is not a dc-dc converter- it is a relay, Pzgouras did not spare expenses.
The black wires are connected to the gate. Thea are really longer, I just had cut them, please note the gate resistor, next to the mosfet driver ic on the right of the main board.
How does one get away with 2,5 inch long gate wires? How can a gateresistor be that small? Well if you operate the IGBT and the driver at only 50hz way below at least 5kHz according to data sheets.
Pay attention to the soldering of the bottom side of the master piece - truely a Gouraz engineering.
Oh, thats it! There is nothing more in the, I admit very light plastic box, that is glued together by silicon, except 2 igbts.
Thats why a 25KW motor can easily to blow 2 brand new 1200V igbts.
By the way, the ep Jr is rated for some 300V, 500A, it bew up on a 120V 250A system- because:
No opocouplers, no dc-dc seperation of ground, no overcurrent protection, long leads everywhere, no built in main caps....
Pzgouraz is dreaming if he thinks and also writes in is manual to use external main caps- because every inch of wire lenth results in transient voltages that can kill any fet igbt in no time, even at 50Hz. There it doesn`t occur that often, but it does. The same also goes for the diode.
Thats the reason why no manufacturer leaves out on those parts, they would if they could.
Back to school I would have recommended, pertaining also to the soldering work, but Mr Pzgouraz probably is used to change names and sceemes quickly, but he sure won`t sell many ep juniors.
It is actually a microcontroller operated PWM controller. The board with the leds is where the throttle is wired to, it`s purpose is to generate the pwm.
Thats the only thing the 8 pins Atmel does here. The leds dont have any purpose, the board is cannibalized from some chinese toy.
The black cube is not a dc-dc converter- it is a relay, Pzgouras did not spare expenses.
The black wires are connected to the gate. Thea are really longer, I just had cut them, please note the gate resistor, next to the mosfet driver ic on the right of the main board.
How does one get away with 2,5 inch long gate wires? How can a gateresistor be that small? Well if you operate the IGBT and the driver at only 50hz way below at least 5kHz according to data sheets.
Pay attention to the soldering of the bottom side of the master piece - truely a Gouraz engineering.
Oh, thats it! There is nothing more in the, I admit very light plastic box, that is glued together by silicon, except 2 igbts.
Thats why a 25KW motor can easily to blow 2 brand new 1200V igbts.
By the way, the ep Jr is rated for some 300V, 500A, it bew up on a 120V 250A system- because:
No opocouplers, no dc-dc seperation of ground, no overcurrent protection, long leads everywhere, no built in main caps....
Pzgouraz is dreaming if he thinks and also writes in is manual to use external main caps- because every inch of wire lenth results in transient voltages that can kill any fet igbt in no time, even at 50Hz. There it doesn`t occur that often, but it does. The same also goes for the diode.
Thats the reason why no manufacturer leaves out on those parts, they would if they could.
Back to school I would have recommended, pertaining also to the soldering work, but Mr Pzgouraz probably is used to change names and sceemes quickly, but he sure won`t sell many ep juniors.
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Yep, a whole lot different than the 1000
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Thank you very much. I inserted the images to make them easier to view.
major
From eBay lisiting and web site: http://www.ebay.com/itm/230689834392
It is a light dimmer kit which the maker says can be used for speed control.
The point is that you knowingly use a crappy little "kit" circuit board in a product which you sell for propulsion system control in automobiles which can find their way onto public roads. This is totally irresponsible and dangerous. Should someone end up being injured or killed due to your "product", I hope that the litigation will find you personally responsible and warned here and send you up river for a long while to think about it.
Get your crap off the market.
major
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Also sad is that this crappy little circuit board is a much higher quality than the rest of the control circuitry.![]()
The point is that you knowingly use a crappy little "kit" circuit board in a product which you sell for propulsion system control in automobiles which can find their way onto public roads.
My ep Jr only had 1 gateresistor - for 2 IGBTs and the gate wires were only 2 inch long.
But unevenly long, one was shorter than the other!
When I received the piece, I looked inside to see what`s inside. First I thought to not even install it in the car, because I didnt believe that it would work at all.
When I tried it on a lightbulb, I noticed a 50 Hz humm. The osci proofed I heared right.
Since I have never seen or heared of any igbt operated on such a low frequency I gave it a try. I was surprised to see it work- for some hour. Than it gave up.
Must be the very low frequency that it gets away with such long gate wires and such small gateresistors.
This igbt drive incorporates ALL the dont´s one can read up in ap notes and data sheets.
Btw, the datasheet for those ibts list frequencies of 5kHz- 20KH
z
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