methods
1 GW
Goal high level: Low cost "contactor" (in this case breaker switch) suitable for 150V @ 100A continuous DC to be used as part of a low cost, IP67, final stage in a modular BMS that spans 4S to 30S. We want mosfet drive quiescent current (so... microwatts) with contactor simplicity and robustness.
Looking for: Quality brand name that sells in volume (we need these cheap, so not the top of the line) where ideally a single form factor covers multiple trip ratings as with a standard breaker
Big Moose suggested in another thread the novel idea of attaching a solenoid to a breaker to turn it into a latching contactor.
You would manually set it.
It would break in the case of short circuit
The BMS could force it to break in the event of XYZ via the solenoid
It would always require manual reset... and this is fine... because nobody should be bouncing off of BMS limits. The Controller should handle LVC, the charger HVC, and precharge for big spikes.
(Hmmm... now that I think about it... eh... we will need to be able to reset that quickly)
Comparable DC contactors go for about $100 but draw 1W to 2W continuous to operate.
Comparable LATCHING DC contactors go for about $150 and draw nothing
Comparable Mosfet stage... can get really expensive... if we want it to be as reliable as a contactor or breaker against gnarly capacitive loads etc. Maybe not expensive in production but certainly expensive in Engineering design hours, qualification, heat sinks, ... meh. So voltage sensitive as well... and a lot of work in production.
Starting to dig now.
Will start with major retailers and work backwards for some economy of scale choices.
We want to make a 150VDC 100A latching relay for an order of magnitude less than Gigavac (who already totally undercuts other high reliability brands).
-methods
Looking for: Quality brand name that sells in volume (we need these cheap, so not the top of the line) where ideally a single form factor covers multiple trip ratings as with a standard breaker
Big Moose suggested in another thread the novel idea of attaching a solenoid to a breaker to turn it into a latching contactor.
You would manually set it.
It would break in the case of short circuit
The BMS could force it to break in the event of XYZ via the solenoid
It would always require manual reset... and this is fine... because nobody should be bouncing off of BMS limits. The Controller should handle LVC, the charger HVC, and precharge for big spikes.
(Hmmm... now that I think about it... eh... we will need to be able to reset that quickly)
Comparable DC contactors go for about $100 but draw 1W to 2W continuous to operate.
Comparable LATCHING DC contactors go for about $150 and draw nothing
Comparable Mosfet stage... can get really expensive... if we want it to be as reliable as a contactor or breaker against gnarly capacitive loads etc. Maybe not expensive in production but certainly expensive in Engineering design hours, qualification, heat sinks, ... meh. So voltage sensitive as well... and a lot of work in production.
Starting to dig now.
Will start with major retailers and work backwards for some economy of scale choices.
We want to make a 150VDC 100A latching relay for an order of magnitude less than Gigavac (who already totally undercuts other high reliability brands).
-methods
