Help designing a SSR ( solid state relay)very low voltage <5 volt , very low impedance<5mho must be "D"= "C" except MBB make before break) ,

Seeking help designing a SSR ( solid state relay)very low voltage <5 volt , very low impedance<5mho must be "D"= "C" except MBB make before break)
Very slow repetition rate
Form "D" SSR with the following specification this is nothing more than form "C" except MBB ( make before break contact
Design goals in order of priority :
1: >bidirectional 50 Amps DC minimum design concept can be proven at lower rating 5-10 A, must capable to be step up into hundred of A ( of course driving power requirement will change )
2: Voltage across the N.O. & N.C will never be over 5 Volts , MUST be bidirectional
3: Rdon < 5 milliohms (the lower the better)
4: Signal driving power <10 milliwatts ( 5 volt @ 2 ma) isolation >600 volts (Signal to FET mosfet ) just like a standard relay only power consumption is to the relay coil,
normal operating power after contact transfer AS LOW AS POSSIBLE < 1 milliwatts be nice Been looking at the HT0440 as dual gate driver for the 4 FET making up the Form "C" arrangement

5: activation time <1- 2 seconds ( from the moment the driving signal is applied, switching function have several seconds to
actually do the transfer, the switching transfer (shorting across all contact )must be quick as possible (< 1 usec desirably)
most important is the MBB (make before break).
Those are design goals specifications , some spec are negotiable.
Able to compensate toward a project completion in cash payment or partnering in marketing of it ( believe there is a large untap need )

Latching contactor satisfies all but coil power. An example.


Can you rob power from primary source you are switching for pulse coil operation ?


Regards, Dana.

That is a very specific list of requirements. Is this school work? Or, is this for a commercial / MIL product/project? In either case, why should we do all the work?

Please show your progress so far, for us to comment on.

ak

Danadak , thank you for your suggestion, have no power to take, only about 100-200ua ( from 10-15 volts ) which can be accumulated over a period of time 1-2 second and dumped into the FET gate , been looking at the HT0440 trying to figure out how to store it and drive the gate on hard .

You have to compute the gate charge you need to charge the MOSFET gate capacitance,
while keeping the driver in operation. Normally one thinks of AMPS to rapidly charge the
MOSFET gate C so that it spends minimal time in linear region hence dissipating minimal
power.


**broken link removed**



Regards, Dana.