dc/dc ssr problem

bertus

Joined Apr 5, 2008
22,921
Hello,

What is the partnumber of the DC/DC SSR that you are using?
In the attached datasheet there is the "off state leakage current" given of max 1μA.

Bertus
 

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Thread Starter

kwhkwh

Joined Jul 19, 2016
34
hi al,l I have used a fotek dc/dc 100 amp output from ebay, with a max 40 amp output pwm, I supplied 9v to the pwm and connected output to ssr input ,I then connected a small dc motor to output of ssr using 9v supply and a blocking diode without turning on pwm, the motor ran, I disconnected pwm and still the motor ran. I then connected my mutimeter to out of ssr and it showed zero. could the ssr be faulty. I tested the pwm with the 9v motor on its own and it works great, but I wanted the ssr to control a high current heater thanks for any help... great site...kev
 

Thread Starter

kwhkwh

Joined Jul 19, 2016
34
Show circuit!
Max.
hi I bought a 40a max pwm works fine I then bought a fotek 100a dc/dc ssr off ebay I connected 9v to input of pwm and output to input of ssr ,output of ssr to small dc motor with 9v supply including diode. without imput from pwm motor ran when 9v applied disconnected pwm completely motor still ran could it be a faulty ssr...thanks kev
 

bertus

Joined Apr 5, 2008
22,921
Hello,

The SSR is likely a DC/AC relays.
It will not turn off with DC.

As said before, Give us a link to the used SSR.

Bertus
 

MaxHeadRoom

Joined Jul 18, 2013
30,654
I don't get how you are configuring PWM to a SSR??
What are the details of the PWM.
Why introduce a SSR?
Is this one of the Ebay $5.00 specials?
Max.
 

Thread Starter

kwhkwh

Joined Jul 19, 2016
34
I don't get how you are configuring PWM to a SSR??
What are the details of the PWM.
Why introduce a SSR?
Is this one of the Ebay $5.00 specials?
Max.
hi I wanted to use the ssr as a high current pwm controlled supply to a dc heater and yes it is a £7 unit
 

Thread Starter

kwhkwh

Joined Jul 19, 2016
34
Show how you have it hooked up, the motor should not run without any input on the SSR.
What voltage is the heater?
Max.
I connected a 9v + supply to the ssr output I then connected the - supply to the motor and then from the othe motor connection to the negative out put of the ssr including a back emf diode across the motor . without input from the pwm the motor ran at full revs? thanks
 

Thread Starter

kwhkwh

Joined Jul 19, 2016
34
I connected a 9v + supply to the ssr output I then connected the - supply to the motor and then from the othe motor connection to the negative out put of the ssr including a back emf diode across the motor . without input from the pwm the motor ran at full revs? thanks
the heater is approx. 13v I used a small dc motor to test the ssr before running a high current through the ssr
A SSR with no input the output should normally be OFF, .
Max.
thank you this why I think the unit is faulty do you agree thanks for your time
 
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