Warnings ON How to Safely Build With High Voltage DC
This has high voltage and could be fatal if you touch the wrong thing. So normally when I build projects I ground everything required to the case. Well this time it does not work ,nothing is grounded to the case. So a brief explanation . The reason is pretty simple is that it is connected to a small inverter that is only connected to the batteries , which makes it portable and the inverter does not have a ground connection on the back to connect a ground, so there is no ground to connect it to.
1/ I'm using a 24 volt to 220-240acv 2000watt/4000watt peak inverter, next is a 5K 220vac variac to control the voltage level and off on switch is handy. Next a power cable connects to the variac to the high output of the controller (no green wire ground connected to case or inverter will shut off even if variac is not turned on) .
2/ Next is a 50amp bridge rectifier mount on the back of the case and isolated from the heat sink with mica mount under the bridge and a nylon washer to keep the mounting bolt from touch the heat sink, in this case the connection wires set back into the heat sinks to they can't be touched.
3/ Next where the original version shows a 220vac to 115avc transformer running in reverse ,research says this is not a good idea (as they heat up)and these transformers are hard to find. So a voltage doubler circuit is use that also smooths out the dc voltage and has a switch for regular voltage or double voltage using two electolytic capacitors. This power is connected to the mosfets on the heat sink.
4/The heat sink has the 6 mosfets mounted for the three phases, these have mica under each transistor and nylon washers to isolate the mounting bolts. ( there is an extra small heats used because my washers were meant for thicker transistor and were to long) This covers the high voltage.
This is a picture of the controller board circuit, this was created using Express PCB software which is free, and can be sent to the company to supply double sided pcb boards, I can supply a copy by email for no charge if you request one.
There is two ceramic capacitors missing from above circuit 5 volt regulator between input and ground is a .22uf ceramic, between output and ground is 0.1uf ceramic
QTY Description Digi-Key
24 STW72N60DM2AG MOSFET N-CH 600V 66A
UPDATED Drive coming soon.
3 IR2104 DIP gate driver IC IR2104PBF-ND
3 1.3M ohm 0.5 watt resistors
3 10K ohm 0.5 watt resistors
3 33K ohm resistors
6 100 ohm 1/4 watt resistors
3 IN5408 diodes E3154GICT-ND
3 10uf 25volt capacitors
3 2.2uf 25 volt capacitors
3 8 pin dip sockets AE9986-ND
1 5 volt voltage reg 1A TO220-3 Lm805CT/NOP8
1 HEAT SINK TO-220 .250" compact HS105-ND
4 Varistor 910V 4.5KA DISC 14MM (MOV) 495-4653-ND
1 Bridge rectifyer 50 amp
2 CAP ALUM 680uf 20% 400V screw 493-9313-ND
1 12 volt 5 amp power supply with power cord
1 ARDUINO computer (with mount that I used in the case) from NEWARK
1 Chinese clone from www.universal-solder.ca for testing
(works $7.95 from SK CAN. and is the one I used bought on E-bay )