DC SSR only working at half

S

soakes94

New member
Ive built some DC SSR's and connected them to my grinch controlled by a ren-c, i have both cables running between the ren-c and the grinch and both have a power supply. The lights are 12v led's and dim up and down fine however when I measured the voltage of the leds it was only 6v. Ive checked everything and cant seem to find any problem anywhere. Can anyone help?

Thanks in advance Stephen
 
soakes94 said:
Ive built some DC SSR's and connected them to my grinch controlled by a ren-c, i have both cables running between the ren-c and the grinch and both have a power supply. The lights are 12v led's and dim up and down fine however when I measured the voltage of the leds it was only 6v. Ive checked everything and cant seem to find any problem anywhere. Can anyone help?

Thanks in advance Stephen
Click to expand...

Where were you measuring?
Did you try between +V and GND at the DCSSR itself?
 
Remove the LED from the output and measure from the +DC to the output pin and verify if you are seeing 12v there or not with the channel on. Remember these are switched grounds. If that's OK then you know the SSR is working OK.

Can you describe exactly how you have things wired up? Where is the current limiting resistor installed in the path and what do you see across that?

I'm a little confused because you indicated it dimmed up and down fine?
 
Ive attached a picture of my DC SSR, the resistors between the opto and input are 680 ohm, the resistor on the 12v is a 10k ohm and the resistor between the opto and the mosfet is a 470 ohm. The 2 screw terminals read 12v, when I activate the channel to 100% im only getting about 6v out. I take this reading by keeping the positive end of the tester on the 12v screw terminal at the top and place the negative on the output screw terminal.

Can anyone help?
 
What are you using to trigger the DCSSR? Any chance it's doing a PWM at about 50%? (Just looking to rule out the silly .. but sometimes overlooked solutions)

How about a picture of the underside, so we can double check the circuit?
 
It appears you etched your own boards - good for you! Can you list exactly which parts you used for the MOSFET and opto? Just wondering if the FET is not turning on completely or something...
 
Ive set it to 100% and my output is still 6v, Ive attached a picture of the bottom hope it helps

Thanks for all your help
 
Ive used 78L05 for my voltage reg, ive got 680ohm resistors between the opto and input, ive got a 10k ohm on the 12v into the mosfet, and a 470 ohm between the opto and mosfet and im using a RFD14N05L for the mosfet and also a 100nF cap.

thanks stephen
 
Same voltage reading on all four outputs?

What if you don't use the REN-C? (I'm assuming the REN-C F/W wouldn't know that you have DCSSR's attached, so it's output may not be just "ON".. and then later .. "OFF")

Have you got an SSR tester, that you could just close a switch to turn the SSR on? As you are home etching there are a couple of samples in the FILES section. It might help. (The testers usually double as a cable tester as well, so it's a reasonable investment of time to make one)
 
I dont have one so I will make one and get back to you on the results, I took a volt meter and had a look at the input voltages from the grinch which is controlled by the ren-c and I got 2.30 volts, I dont know if this is normal for the ren-c or if it should be 5v like the grinch outputted.

Thanks Stephen
 
christmas-light said:
I am just asking here: The Firmware on the Ren-C, do you not have to set it up to controll DC and not AC ?
Click to expand...

The Ren-C only works with a Grinch or 595 board and does not have any capability for DC or AC. The Ren-C is a translator, of sorts, that translates a serial signal into a format that the Grinch/595 can understand, which normally are connected to the parallel port.
 
dirknerkle said:
The Ren-C only works with a Grinch or 595 board and does not have any capability for DC or AC. The Ren-C is a translator, of sorts, that translates a serial signal into a format that the Grinch/595 can understand, which normally are connected to the parallel port.
Click to expand...

Yes, I know what the Ren-c does, (learned for the wiki ;) ), but I was just wondering, because on a eg. Ren 64 you have to do that :eek:
 
jmksparks said:
Is the program in the ren,c set for 60hz because soakes needs 50hz for the UK. ? would that be the cause.
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The Ren-C code is self-adjusting for 50/60Hz. Also DCSSRs work on active low signals as the ACSSRs do so you do not need to invert the signal out. You only need to change it when using inverting drivers such as ULN2803s or transistors. AFAIK there are no changes to the code required for Ren-C's but Phil could confirm this...
 
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