Islander
Heliman
Location: Stanford, CA
| Has anyone tried to modify the ESC for a higher rating? since a 50V+ ESC is so expensive, is it possible to modofy a JETI77A ESC for 50V?
the prime limitation of operation voltage would be:
1. FET - this is primarily limited by Vds
2. FET driver - the driver would have to output a voltage higher than the DC bus(battery DC value) for at least 10V
3. battery capacitor - this is the one which cause the big spark for your battery connector
4. CPU's power supply - LDO(known as low drop out regulator), should withstand upto 50V
5. S/W - the sensorless sensing circuit/algorithm may not operate right at too high a voltage
6. ???
for a JETI 77 3P-O
1. FET - it is a SI4850, which has a Vds of 60V, should be OK to handle 12S - around 50V
2. FET driver - it is a IR2103S, which can operate up to 600V, should be OK to operate at 50V
3. battery capacitor - this one is rated as 330uF/50V, two in parallel. - It would be better to replace them with two 330uF/100V parts, and these caps are no difficult to get.
4. CPU power LDO - it is a two-stage design which gets each stage a lower voltage to "dropout", one regulator is a NS LM2931, which can withstand 26V. the other is unknown. SO I don't know if it can withstand upto 50V. I think I can find some replacements which would be able to handle 30V, and this would make the whole reguting circuit able to operate upto 56V
5. S/W and sensorless circuit - I have no info about it, but I think it should not be a problem since the circuits is consisted with only a few resistor network.
6. ???
comments and suggestions? |
