Curtis controllers are manufactured by Curtis
Instruments Inc.
1221B
- Operating voltage: 72-120 Volts DC
- Maximum current: 400 Amps
- 15 KHz silent operation
- (no longer in production)
1221C-7401
- Operating voltage: 72-120 Volts DC
- Maximum current: 400 Amps
- 1.5/15 KHz switch frequency operation, audible as a whistle at low speeed.
1231C-7701
- Operating voltage: 72-120 Volts DC
- Maximum current: 550 Amps
- 1.5/15 KHz switch frequency operation, audible as a whistle at low speeed.
1231C-8601
- Operating voltage: 96-144 Volts DC
- Maximum current: 500 Amps
- 1.5/15 KHz switch frequency operation, audible as a whistle at low speeed.
Curtis controllers are available from most EV parts suppliers.
Follow this link for a current list.