FlaMtnBkr Posted March 15, 2015 Posted March 15, 2015 I'm trying to do something that I think is pretty simple but have no idea how to actually do it. I was hoping someone might be able to dumb it down so a monkey can do it including ordering all the right parts. Or if someone has the necessary parts maybe I can pay them to do it for me? Or even better would be an off the shelf unit that will do it. I'm looking for something that can read a temperature and turn a computer fan on below a user set temp, and off above the set temp. I don't know what the temp will be so I will need to be able to change it. Any thought? Anyone want to make a little money? Thanks!
Bobosan Posted March 15, 2015 Posted March 15, 2015 Check Ebay out for something off the shelf. If you don't mind waiting for China shipping something like this can be had reasonable but there are plenty more offerings on Ebay. http://www.ebay.com/itm/AC-110V-Temperature-F-Controller-Temp-Sensor-incubation-thermostat-Switch-Relay-/380744999957?pt=LH_DefaultDomain_0&hash=item58a62ba415
otto Posted March 15, 2015 Posted March 15, 2015 If you're interested in the above option (I can think of some applications) just check "North America" or "US Only" in the location options on the left side (eBay). Most of the time there are identical selections that ship from this side of the pond, usually Cali. Same item, same price, much faster.....
dagabu Posted March 15, 2015 Posted March 15, 2015 I am using two "Dual PID Temperature Controller Thermocouple TD4-SNR Solid state relay SSR-25 DA" for my beer brewer and Keezer, the 25A allows me to trigger up to a 30A circuit and program the heating/cooling set points separately as well as a manual override for maintaining a low boil. The one shown from eBay only has one relay and it does not look to be solid state. THIS ONE can do both the heating and cooling side. Its more money but it ships inside the US but they are widely used by home brewers and they are pretty solid.
FlaMtnBkr Posted March 15, 2015 Author Posted March 15, 2015 Thanks guys. I figured there would be something that was off the shelf but guess I didn't use the right search terms. Do they have a built in thermocouple or one that plugs in somehow? I see what looks like one in the first link but no mention of one in the second.
otto Posted March 15, 2015 Posted March 15, 2015 You get a lot more with "option 2" but there is no thermocouple included. It appears that you could use almost any TC with it: (from the listing) "Input: Thermo Resistor: PT100, Cu50; Thermocouple: J,S,K,E,Wre3 ~ Wre25" I'd expect that two of the terms on the back of the controller would be used for that. The ability to control both heating and cooling plus a really extreme range +/- 1999 could cover lots of projects. I've been thinking of modding my shop oven to be able to cook charcoal. The prospect of controlled temp for higher quality has me thinking.... So Dave, are there pretty good instructions with that unit or do we need a little learning to figure it out?
dagabu Posted March 15, 2015 Posted March 15, 2015 You can get all the parts (SSR & Type K Thermocouple) in many auctions on eBay. Type K will set you back about $3 from china for extras. @Otto, they have horrible, crappy instructions BUT home Homebrewtalk.com has a metric crap ton of info on them and any help you all need for wiring is available from me or from them. It's really as easy as hooking power up to the PID, hooking up the Thermocouple, wires to the SSR/s, power to the SSR/s, set the High/Low temps and run. Even with bad instructions, it takes no more than an hour to figure it out.
dagabu Posted March 15, 2015 Posted March 15, 2015 I'm trying to do something that I think is pretty simple but have no idea how to actually do it. I was hoping someone might be able to dumb it down so a monkey can do it including ordering all the right parts. Or if someone has the necessary parts maybe I can pay them to do it for me? Or even better would be an off the shelf unit that will do it. I'm looking for something that can read a temperature and turn a computer fan on below a user set temp, and off above the set temp. I don't know what the temp will be so I will need to be able to change it. Any thought? Anyone want to make a little money? Thanks! Tell me what the set up looks like and I can build it for you if you wish. I have a 6"x6"x4" project box, a TD4 & TA4-SNR with 40A SSR in stock, input power can be anywhere from 90-260V AC and output can be 30-380V AC.
dagabu Posted March 15, 2015 Posted March 15, 2015 OH! Some type K thermocouples and PIDs will work in lead melting pots, charcoal TLUD makers and even generic thermostats for heating/cooling your shop.
nater Posted March 15, 2015 Posted March 15, 2015 I'm not sure what your end project will be. Here is something similar that I found last fall, but I ended up buying something off the shelf. The instructions are for a BBQ pit controller, it stokes the fire until it reaches the target temp, then stops. http://tvwbb.com/showthread.php?53317-HeaterMeter-Hardware-v4-2-4
rogeryermaw Posted March 17, 2015 Posted March 17, 2015 i'd probably use an arduino with a thermocouple input and a relay on an output to cut power to the fan. the programming is pretty simple done via computer on the usb hub.
dagabu Posted March 17, 2015 Posted March 17, 2015 True but an arduino will cost you more and give you no display or edit on the fly capabilities. Pretty sure the TA4 has a relay out for small loads too.
rogeryermaw Posted March 18, 2015 Posted March 18, 2015 dang...that is a nice controller. especially for under $40. it does have a low power relay but a breadboard and $5 worth of components and you could control much larger loads with it. good find!
Shunt Posted March 18, 2015 Posted March 18, 2015 "I'm looking for something that can read a temperature and turn a computer fan on below a user set temp, and off above the set temp. I don't know what the temp will be so I will need to be able to change it." It would help to have some more details, as to what kind of device you are trying to build. All the replies above are useful, but if you are building something like a simple dry box, might be overkill, and a bi-metal thermostat as used in HVAC might do the job. I have worked as an industrial automation and control tech for decades, and seen many over-engineered systems put into place. Usually because the end user did not really know what they wanted to do. Kind'a like calling a contractor and saying, "I want to build a house! How much will you charge?" Contractor replies, "let me look at your blueprints, and I will give you an estimate". PS, thanks to dagabu for this link http://www.ebay.com/itm/110880595387?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT I did not know they were available for THAT cheap! In my last good job we uses Siemens, Allen Bradley, and sometimes GE for mission critical applications as we knew we could rely on then for tech support. Automationdirect.com has a good reputation for the low end product as well now.
FlaMtnBkr Posted March 18, 2015 Author Posted March 18, 2015 I want to make a fire box that warms a container. It will be closed off except for a pipe with a computer fan that forces air in to stoke a wood fire. When it gets too warm it will shut the fan off and hopefully cool down the fire with the fan off. Just an idea I want to try.
rogeryermaw Posted March 18, 2015 Posted March 18, 2015 have you chosen dimensions for your fire box? computer fans don't move a lot of air, but may be sufficent for your purpose, but if the box is large, i have doubts that a computer fan will feed your fire well. other inexpensive choices are available though. look toward air mattress inflators or hair dryers.
Shunt Posted March 18, 2015 Posted March 18, 2015 http://thumbs4.ebaystatic.com/d/l225/m/mAfUM92GsvZqVZ0CiVoUX8Q.jpgAs Roger said, a computer fan may not be the best solution. You possibly could use a heater like this, disconnect the internal heating elements, and relocate the thermostat to the container you are warming. The fan motor is rated for more or less constant duty, and you would also have everything running on 120 VAC and not have to fool with the 12VDC computer power supply. The entire unit costs about $25.00. Just trying to keep it simple for you, hope this helps.
FlaMtnBkr Posted March 19, 2015 Author Posted March 19, 2015 Thanks guys. I will pick one and give it a try at some point. I don't have a design yet but it won't be super big to start. I'm thinking of the fire box on my smoker and the damper to let air in is quite small and that is passively pulling air in where I will be actively forcing it in. But if it isn't big enough and has a relay I should be able to easily size it up. I might have some questions down the road but think I can at least get the ball rolling with all this great info. Thanks again!
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