Temperature Meter for SSTC's and DRSSTC's / Projects / Forums

Forums

4hv.org :: Forums :: Projects

« Previous topic | Next topic »

Temperature Meter for SSTC's and DRSSTC's

1 2 next

Move Thread

LAN_403

MRacerxdl

Mon Feb 18 2008, 08:16PM

Registered Member #989 Joined: Sat Sept 08 2007, 02:15AM
Location: SÃ£o Paulo, Brazil
Posts: 476

Hi all, I have made a little project here, for measure the temperature of a heatsink or another thing.

What it uses:

LM35 (I used the LM35DT, that is on TO-220, and I can put it on the heatsink)
741 (Amplifies the Signal from LM35)
3914 (For Bargraph display)

A few resistors and few caps.

Ok, it has 10 Leds on the bargraph display. The Bargraph display will be 10ÂºC per Led. That means if you have no leds turned on, that is on 0ÂºC, and if you have all leds turned on, its 100ÂºC or more.
Here is the schematic:

As you can see, the circuit its not too complex, I didnt see any of these here on 4hv forum. The only schematic that I see, its one with LM311, but LM311 its more expensive than 741 (Because it can work with higher frequencies with out internal noise). And for that aplication its not nescessary a good OAMP, the convetional LM741 will do good the work.

Here is a PCB that I have made, I dont have any photos of the schematic builded because I tested it on the breadboard.

Sorry for the low quality images, I am using paint to convert the BMP files of Proteus to JPG, I didnt install photoshop now, I will put it later :P

I hope someone use it :P

PS: I am planning to make a new one, that doesnt need Simmetric Power Supply, with the LM386 OPAMP.

Bauerb2

Mon Feb 18 2008, 11:09PM

Registered Member #973 Joined: Tue Aug 28 2007, 07:32PM
Location: Pittsburgh, PA
Posts: 66

i've always thought about putting a mod like this into my computer on the CPU heatsink and let it light up the inside of the case as the temp changes.

wouldn't it be better if you used serparate resistors for each led? i think red, yellow and green draw a different amounts of current.

MRacerxdl

Tue Feb 19 2008, 08:54AM

Registered Member #989 Joined: Sat Sept 08 2007, 02:15AM
Location: SÃ£o Paulo, Brazil
Posts: 476

In normal operations that's a good think, but the LM3914 divides equally the current through the leds, making these bright equally.

Dr. Drone

Tue Feb 19 2008, 03:47PM

Registered Member #290 Joined: Mon Mar 06 2006, 08:24PM
Location:
Posts: 1673

MRacerxdl

Wed Feb 20 2008, 08:48AM

Registered Member #989 Joined: Sat Sept 08 2007, 02:15AM
Location: SÃ£o Paulo, Brazil
Posts: 476

Yeah, that Infrared termomether is good too, but I made this to fix on sstc's and drsstc heatsink, or in other parts. I think it will be usefull.

Rollingblackout

Tue Jun 16 2009, 11:27PM

Registered Member #1524 Joined: Sun Jun 08 2008, 05:25PM
Location: Grand Junction, Colorado
Posts: 38

Great circuit thanks for posting it. My brother keeps burning up r/c truck engines due to overheat, I think ill mount the to-220 on the cyl. head and stick the leds in the body.

Killa-X

Wed Jun 17 2009, 01:54AM

Registered Member #1643 Joined: Mon Aug 18 2008, 06:10PM
Location:
Posts: 1039

I had this thought awhile back ago, except i was thinking of microcontrolleres. "What If I mount a sensor to the heatsinks for a SSTC, so when it runs too hot, the system automatically shuts off for fans to cool it, and turns back on after its been cooled.

You know, so you don't risk killing mosfets due to heat, let the system do it for you :)

uzzors2k

Wed Jun 17 2009, 02:56PM

Registered Member #95 Joined: Thu Feb 09 2006, 04:57PM
Location: Norway
Posts: 1308

Nice idea. It would be quite practical for hot-running SSTCs or DRSSTCs, and really look good on a front panel.

Killa-X wrote ...

"What If I mount a sensor to the heatsinks for a SSTC, so when it runs too hot, the system automatically shuts off for fans to cool it, and turns back on after its been cooled.

I did this for a magnetic levitator I built, using a thermristor. A microcontroller would be overkill as a few op-amps could handle both sensing the temp and hystersis for the control loop.

tobias

Wed Jun 17 2009, 05:47PM

Registered Member #1956 Joined: Wed Feb 04 2009, 01:22PM
Location: Jersey City
Posts: 172

Uzzors wrote...
I did this for a magnetic levitator I built, using a thermristor. A microcontroller would be overkill as a few op-amps could handle both sensing the temp and hystersis for the control loop..

Yeap! One opamp as a signal amplifier to LM35 and one as a comparator with hysteresis connected to a relay on mains or the gate of switching mosfets do the trick. =)

The good thing about using the LM35 is the linearity of the output voltage/Celsius.

Interesting job MRacerxdl!!

Austin

Wed Aug 19 2009, 03:29PM

Registered Member #1169 Joined: Wed Dec 12 2007, 09:16AM
Location: Portland OR
Posts: 251

I like this a lot, in fact i might use it for my next build. thank you

1 2 next

Moderator(s): Chris Russell, Noelle, Alex, Tesladownunder, Dave Marshall, Dave Billington, Bjørn, Steve Conner, Wolfram, Kizmo, Mads Barnkob