Digidoc 5 - stop the annoying on/off/on/off?

[Som]

Another question for you knowledgeable people!
I've got a Digidoc 5, which does exactly what it says on the tin, but I find the constant on/off/on/off of the fans annoying. You know, the GPU (or whatever) gets to the preset temp, the Digidoc fires up the fan and 2 seconds later the temp is down enough for the fan to turn off. Repeat cycle endlessly.
I have tried moving the sensors about which helps, but the problem is built into the way Digidoc works.

So, I have come across this;
Ioss RD7 System aftercooler (http://www.ioss.com.tw/web/English/RD7%20CA.htm)

It's a timer to keep fans running for a few minutes after a pc is shut down. But it would be perfect to keep the Digidoc fans running long enough to really cool things down - enough to stop the constant on/off cycle.

Just need some sort of relay/timer device to be triggered by the 12v supply from the Digidoc but power the fan itself for a few minutes.

Any idea if this 'aftercooler' could be modified? Or is there a better way?!

Thanks,

Som

[bigben2k]

You could simply add a relay with a timer, at the output of the DD5. As for keeping a fan running past the shutdown point, that's another story.

[Som]

>>You could simply add a relay with a timer, at the output of the DD5

I like the simply :) Can you elaborate, please?

>>. As for keeping a fan running past the shutdown point, that's another story.

If you mean re-create the aftercooler device, that's not what I want to do - I just thought it might be possible to mod it for my own purposes...

[bigben2k]

All right.

First, you have to have a 555 timer circuit, that starts a 2 minute countdown. It must be triggered by the DD5 output. You can find the 555 timer circuits very easily, with a google search.

Since the output of the timer isn't anywhere near enough to drive a fan, you can make the 555 output drive a small relay, which in turn drives the fan. Just make sure that you spec out that relay very carefully, because you don't want to overload the timer.

[Som]

>>You can find the 555 timer circuits very easily, with a google search

You're not wrong there! :cool: I'll try to work something out...

I'm no electronics guru though, so if anyone has some details about a suitable module, please let me know. I can source and connect the bits, I just don't know how to design the circuit.

Thanks!

[Som]

There really is a LOT of information about 555 timers out there!
I think I've found the right circuit;
'555 timer Mono stable (one shot) circuit' on http://ourworld.compuserve.com/homepages/Bill_Bowden/page9.htm .
Out of the blue I find myself learning some electronics!

[bigben2k]

Good show. Now to adapt it to the output of the DD5...

[logosmani]

did u ever get this going? just looking at doing something similar atm

[Som]

Er, sorry, no. I invested in a much quieter fan and have it running all the time, so the on/off issue went away. Just use the DD for temp display really.
Still seems like an interesting project though...
Good luck!

[logosmani]

k, shame that :)

well, my problem is that i use the digidoc to raise the speed on my fans, not turn them on as such. The fans are always on on a low voltage, but when the temperature rises the digidoc powers a relay which switches the fans to full throttle. Unfortunately it does that on/off thing a lot and the sound the relay makes going on and off so much is far worse than anything my fans ever put out.

Although i was thinking looking at the 555 in the monostable/one shot setup looks good 'as is' (from the link above) i wasn't sure if the circuit shown starts the timer from when the input switch is released (ie. off) or if it starts it from its initial make. In otherwords, will it, if the digidoc keeps the 'fan' on for longer than the timed delay its set for turn the fan off? or will it perhaps turn it off + then on again everytime the delay expires + is then refreshed? that make sense?

can anyone with 555 experience help with that question?

[JSimmons]

It sounds like you guys need a circuit that speeds the fans up/slows them down according to temperature. Didn't somebody post a link to such a thing not too long ago?

[Som]

>Although i was thinking looking at the 555 in the monostable/one shot setup looks

My plan was to use another relay - DD voltage triggers the extra relay which acts as the start switch to the timer circuit. Once the timer is running the DD/extra relay reset themselves because the fan cools everything down (:eek: ). Timer continues for x minutes regardless.

[sevisehda]

After a month with the DD5 and waking up because some started a DL or my comp warmed up and the fans went on/off or the DD5 started to beep. I just ran all the ground/power lines for the fans to my rheobus and the RPM sensors to the DD5 and used it as an RPM monitor and let it warn me if one failed.

The DD5+ isn't a big improvement minus the front USB/Firewire which most new cases come with anyway.

What they need is a DD6 with(in order of necessity):
...temp range of -30 to 100C...
...ON/OFF or throttle option...
...backlit color options...
...parallel/serial/usb interface...
...software...
...me beta test it...