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Materdaddy
11-13-2012, 01:34 AM
I'd like to use a DCSSR to switch power for a DIGWDF 675 board which requires 5V. In lieu of jumping the 7805 for 5V operation (from the wiki on how to switch 5V) can I simply feed it ~7V and the regulator's Vf will lower the voltage to about 5V such that the output voltage is 5V? I'm not very familiar with how these DCSSRs work.

budude
11-13-2012, 01:52 AM
No - it doesn't work that way - - the regulated output from the regulator is only there to power the opto-isolator output side. If you feed it 7v, you'll get 7v on the DC outputs...

Materdaddy
11-13-2012, 02:24 AM
No - it doesn't work that way - - the regulated output from the regulator is only there to power the opto-isolator output side. If you feed it 7v, you'll get 7v on the DC outputs...

That's what I was afraid of... when I use a 5V supply and I use a jumper across pins 1-3 of the 7805 I appear to be getting 5V out of the expected channel output, but for some reason it's not working for powering my DIGWDF 675. I can however take the output of the 5V supply and wire it directly to the 675 board and have it run properly. I'm wondering if there's some sort of issue with my setup and the SR32 I'm using to test the DC-SSR setup where it's sending some PWM'd signal to the SSR. I guess more testing of other components needs to be done. Thanks for the reply!

Mactayl
11-13-2012, 05:11 AM
That's what I was afraid of... when I use a 5V supply and I use a jumper across pins 1-3 of the 7805 I appear to be getting 5V out of the expected channel output, but for some reason it's not working for powering my DIGWDF 675. I can however take the output of the 5V supply and wire it directly to the 675 board and have it run properly. I'm wondering if there's some sort of issue with my setup and the SR32 I'm using to test the DC-SSR setup where it's sending some PWM'd signal to the SSR. I guess more testing of other components needs to be done. Thanks for the reply!

The SR32 will be sending out a PWM signal to the SSR.

Materdaddy
11-13-2012, 10:52 AM
The SR32 will be sending out a PWM signal to the SSR.

We're now in the wrong forum for this, but is there a firmware change to make it just 5V without PWM?

kychristmas
11-13-2012, 11:05 AM
Seems like a bit of a Kludge to me. In the normal REN world, you can turn PWM off on a single PIC. So it will effect only 8 channels. If you can/do disable PWM on the Ren32, it will effect all 32 channels.

My suggestion would be to simply build a Relay-based based board instead of using SSR. I wasn't running a controller, but I did it my first year to switch 110v to a Animated Reindeer. I'm guessing its the Voltage Regulator on the controller that doesn't like the PWM? Is that correct?

Materdaddy
11-13-2012, 11:28 AM
Seems like a bit of a Kludge to me. In the normal REN world, you can turn PWM off on a single PIC. So it will effect only 8 channels. If you can/do disable PWM on the Ren32, it will effect all 32 channels.

My suggestion would be to simply build a Relay-based based board instead of using SSR. I wasn't running a controller, but I did it my first year to switch 110v to a Animated Reindeer. I'm guessing its the Voltage Regulator on the controller that doesn't like the PWM? Is that correct?

The plan will be to run this from a Renard 64XC which is still in storage, I'm just using the Simple Ren32 for testing right now. I had made the assumption that at intensity of 255 (full on) the output wouldn't be PWMd and I could test my setup this way. Now I need to get the 64 out and see if I can get it working with this setup.

budude
11-13-2012, 11:32 AM
I don't quite understand the issue at hand - a PWM signal from the controller is just a single variable width square wave - on for the percentage you specify, off for the rest - it is not a bunch of separate pulses. The alternative method of turning on SSRs (aka non-PWM) is a single ON pulse (well - two actually) that turns on a TRIAC which self-latches on. Of the the two, PWM would be the much better choice but - I'm not sure it's the right choice... Why do you want to turn them on/off at the DC level?

Utimgr
11-13-2012, 11:51 AM
SSR are typically, if not always, an opto device. This means there is an LED inside, that is controlling the other side, for a DC type application probably FETs or back to back FETs depending on how much current your trying to push thru it. So you can control it with various voltage levels, you just need to calculate the current limit resistor (not being familiar with the circuit) to make sure you don't exceed the forward current, but turn it on hard enough to trigger the output side. For AC, its much the same but rather than FET your going to have a triac. Again, its opto controlled so just use ohms law to calculate the forward current, knowing the drop across the LED when its on.

Materdaddy
11-13-2012, 12:01 PM
I understand what PWM is, but the symptoms point to the SR32 sending a PWM value for 255. With a channel value of 255, I would think that to be 100% duty cycle, or an "always on" signal. However, that isn't powering my DIGWDF675. It seems to be stuck in a reset or something because I can see the tiniest flicker of light coming from one of the strobes. I haven't verified that the output was PWMd causing the failure yet, I just mentioned it, then Mac replied saying it was PWM. My problem could be something to do with the DC SSR too.

If I power the DIGWDF directly using 5V it works, through the SR32 (at value 255 or what I believe is 100%) -> DC SSR, it doesn't work. I measure the power at the output using my DMM to be 5V, so I'm not exactly sure what's going on when going through the DC SSR.

budude
11-13-2012, 12:13 PM
Gotcha... perhaps it's resetting the output to 0 for one time interval at the ZC interrupts... Maybe adding a cap across the output would hold it up better but not sure if the PIC output would like that when it turns off and it's fed DC in from the cap for a moment...

Mactayl
11-13-2012, 12:44 PM
There is going to be a small pulse even at an 255 intensity level at the end of the period around 5ms so that be be what you are seeing. The SR 32 is not setup to turn on/off the output at a solid level (high/low). The PIC firmware is setup for PWM for LED's or ZC for incans.

Mactayl
11-13-2012, 01:05 PM
Did you try changing the state of the output on the PIC in the .inc file as shown in this text file..

Materdaddy
11-13-2012, 01:08 PM
Did you try changing the state of the output on the PIC in the .inc file as shown in this text file..

No, I'll try this when I get a chance tonight, thanks for the suggestion.

Does anybody know if the Renard firmware for 16f688s has the same behavior (small pulse, even at 255 intensity) since that's what I plan on using for the actual show setup?

kychristmas
11-13-2012, 01:10 PM
Did you try changing the state of the output on the PIC in the .inc file as shown in this text file..

Aren't you clever. Using for "include" files for one of their intended purposes. I looked through the .asm files and thought, I guess you can't disable PWM with a SR32. I was clearly wrong and even better you can do it per output?

Nice work Mac.

LightUp
11-13-2012, 01:17 PM
Or you could take the SSR output and add a diode (say a 1N4002) to isolate the filter capacitor. However, this will also lower the 5V output by about .7V
This technique would provide a more steady DC voltage for your DIGWDF675. The capacitor would need to be selected such that there is no practical voltage dip.

Mactayl
11-13-2012, 01:21 PM
Aren't you clever. Using for "include" files for one of their intended purposes. I looked through the .asm files and thought, I guess you can't disable PWM with a SR32. I was clearly wrong and even better you can do it per output?

Nice work Mac.

Phil Short and Peter Rogers incorporated those functions way back when they first came up with the Simple Renard 16 and I have used it on all the Simple Renards ever since....

CaptKirk
11-13-2012, 02:20 PM
And Phil is DEFINITELY one clever person...

P. Short
11-13-2012, 02:43 PM
The intent of the PIC16F688 firmware design was that a dimmer level of 255 would result in an output that was always on (i.e. no pulsing off, not even narrow pulses). This was for use with zero-crossing type optos, if I recall correctly. Off-hand, I don't know if this is still true after a number of firmware revisions.

Materdaddy
11-13-2012, 02:55 PM
The intent of the PIC16F688 firmware design was that a dimmer level of 255 would result in an output that was always on (i.e. no pulsing off, not even narrow pulses). This was for use with zero-crossing type optos, if I recall correctly. Off-hand, I don't know if this is still true after a number of firmware revisions.

I'll have the 64 out this weekend to check that. I'm also hoping that Mac's include file change fixes it for the SR32 for my testing. I'll report back when I know. Thanks again to everybody for the help.

Materdaddy
11-14-2012, 12:16 AM
Did you try changing the state of the output on the PIC in the .inc file as shown in this text file..

Making your suggested change has given me confidence in the DC SSR!

I'm assuming this change inverts the power for the associated pins. Instead of sinking (what controllers typically do to switch on an SSRs) the pin is driven.

I'm also guessing that the 5mS pulse you mentioned comes from a ZC ISR turning everything off, then turning pins off/on based on a table? Inverting it seems to have removed the pulse because when it's "off" it's "on".

Meaning that when I give the channel 0, the output of the SSR is on without pulse and I can test my DC SSR -> DIGWDF675 setup, and when the channel value is 255 the output of the SSR is off (with short pulses of being ON that I can't see because they're 5mS).

Whether these assumptions are correct or not, when sending 0 for the test channels that I inverted, my DC SSR->DIGWDF675 setup works. This does prove that the DC SSR and DIGWDF675 are working as expected, now the main question for me is: Does the 16f688 firmware work as Phil remembers? I'll find out over the next week or so when I get the Ren64 out of storage!

budude
11-14-2012, 01:12 AM
I would say so - I'm using PWM/DC 16F688 code on the Ren48 and it's got a solid output when turned on - also there are no ZC interrupts since the MCLR line is tied high...

Materdaddy
11-18-2012, 12:10 AM
I would say so - I'm using PWM/DC 16F688 code on the Ren48 and it's got a solid output when turned on - also there are no ZC interrupts since the MCLR line is tied high...

Confirmed today by actually trying the entire setup on a Renard 64. Renard 64->DCSSR->DIGWDF675->DirkCheapSSR->Strobes. Worked as expected!

P. Short
11-18-2012, 12:15 AM
As expected or as hoped? I guess that I'm allowed to be snarky here, since I wrote the Renard firmware.

Materdaddy
11-18-2012, 01:30 AM
As expected or as hoped? I guess that I'm allowed to be snarky here, since I wrote the Renard firmware.

Well, I was hoping, but I think you and Brian were expecting... :razz: