BD brake power supplies comparison

BD3 is a new, advanced brake power supply that offers faster eddy current brake control and higher current capability than BD1.
BD2 offers high current capacity and high voltage supply with low cost and passive cooling.

  BD1 BD2 BD3-22.5A BD3-30A BD3-45A
Continuous current specification

17.5A @ 40°C ambient
20A @ 25°C ambient

30A @ 40°C ambient
45A momentary

22.5A @ 40°C ambient

30A @ 40°C ambient

45A @ 25°C ambient
40A @ 40°C ambient

Dimensions 18cm x 13cm x 9.5cm 14cm x 12cm x 12cm 14cm x 15.5cm x 12cm 26cm x 23.5cm x 11cm
Mass 0.6kg 1.1kg 1.3kg 3.3kg
Cooling type Fan Passive Fan and radiator outside of electronics compartment
No worry about dirt ingress
Power supply configurations 1-phase 120V
1-phase 230V
3-phase 120V (208V)
1-phase 120V or 230V
3-phase+neutral 120V(208V) or 230V(400V)
Brake charge time
Frenelsa F16-160
0A ⇒ 15A
1-phase 230V
3-phase 230V(400V)
Brake discharge time
Frenelsa F16-160
15A ⇒ 5A
100ms 4ms
Brake discharge time
Frenelsa F16-160
15A ⇒ 0A
1500ms 12ms
Brake charge time
Frenelsa F16-GR
0A ⇒ 22A
3-phase 230V(400V)
Brake discharge time
Frenelsa F16-GR
22A ⇒ 5A
Brake discharge time
Frenelsa F16-GR
22A ⇒ 0A
Control Pulse Width Modulated input controls brake Pulse Width directly Brake current is controlled internally in closed loop by a fast microcontroller
PWM input or CAN-bus sets brake current target
Diagnostics CAN-bus: brake current and controller temperature feedback
Additional information possible in future with firmware updates
Comparison of steady state operation with BD1 and BD3.

Which power supply should I get?

Recommendation based on dynamometer types:

  • Engine dynamometer, hub dynamometer, low inertia dynamometer: BD3
  • Roller chassis dynamometer with typical inertia: BD1/BD2 is sufficient, but BD3 will get you better control

I want most economical solution.
Take BD1/BD2. It will work with all dynamometers, however on low inertia dynos, speed control won’t be as fast and precise as with BD3.

I want the best solution.
Take BD3, it will provide you with probably the fastest torque response on the market. You can compare charge and discharge (or magnetization and demagnetization) times with competition products.

My brake needs 22A current. Should I get 22.5A or 45A BD3 version to be safe?
You should get BD3 22.5A version. It could deliver continuous 22.5A in 40°C ambient temperature for unlimited time. 45A version is bigger, heavier, and it will cost you more.