Bringing up an old thread as I'm interested in the mosfet idea of a 2 fan set up.
Lonewolf: How would this work with 2 mosfets instead of 1 relay?
Do you mean to use the one standard sender and a mosfet for each fan to prevent the amperage surge of 2 fans that would normally burn out the radiator temp. sender?
Yes, using MOSFETs could prevent the quick wear of the thermal contact in the radiator,
because in this case only the source-drain current goes through the contacts which is
much much lower than the current required by the cooling fan (and there are no inductive
Of course it's possible to assemble a two MOSFET configuration.
The following things are need to consider:
- the MOSFETs will require heatsinks
- the heatsinks will be on different potential relative to chassis, which may lead to unwanted
short circuit, unless you isolate MOSFETs galvanically from the heatsinks.
But the heat conductivity between the MOSFETs and the heatsinks still need to be provided
- the whole stuff needs to be near to the cooling fans in order to reduce the voltage
drop on the fan supply wires
- some neat, water resistant casing may required
Do you have a diagram?
It depends what is the goal, e.g.:
- just take the load off from the thermal contacts and/or
- provide soft start of the cooling fan(s) to avoid the high starting currents or
- temperature dependent dynamic speed control of the fan(s)
This last option will require an NTC or PTC thermistor as well.
Or easier just with a relay I think.
Absolutely it is. I guess i've attached some schematics earlier for this solution.