On another note, some of you need to get a thicker skin! I'm pretty new here and some established members can be hard us new guys. Maybe it's tough love or some are just skeptical. Get over it. You can learn a lot here. To put in terms that a drinker can relate to, this forum is like a bar. There are the regulars, maybe a few surly drunks, whatever. You don't just walk into a new bar (especially one with an established crowd) and find instant acceptance. Come in, have a drink, look around and find your place, make some friends
You will go far here with an outlook like that Tough love. That is a good answer.
FortyNiner wrote:That isn't cheating, that's being resourceful! The $100 (or whatever) you saved is that much more you can spend on 4" copper for the next build.
Where I live, the PC/eco-concious/green crowd call it "upcycling".
I have a 4 foot long piece of 3" copper pipe in the corner of my shop, gonna 'upcycle' that into a flute.
I generally refer to them as environazi's(out here in california they are)
I too, reside in the land of fruits and nuts, in a city known for its "values". Still love it here despite being heavily outnumbered by "them". Also thinking about a flute-finding 12 solid hours to run the Boka is really hard!
I'm looking at SSR's for a 240V controller and I started looking on ebay and I am seeing tons that are rated for even up to 40A for less than $10. The only think I am unsure about is they say that the input rating is for DC, whereas the one on newark just has the 3 and 4 terminals labeled as control pot. My question is would these still work? I realize some of them are probably pretty cheap made and may not last as long, but I think its worth a shot for one that is rated for up to 40A for like 8 bucks. Here's an example:
MisterSteve124 wrote:I'm looking at SSR's for a 240V controller and I started looking on ebay and I am seeing tons that are rated for even up to 40A for less than $10. The only think I am unsure about is they say that the input rating is for DC, whereas the one on newark just has the 3 and 4 terminals labeled as control pot. My question is would these still work? I realize some of them are probably pretty cheap made and may not last as long, but I think its worth a shot for one that is rated for up to 40A for like 8 bucks. Here's an example:
SSRs can have many different inputs. The ones you see on ebay are a 3-32vdc input. That means you need to put 3 to 32v dc accrosed those terminals to switch the high current on. The PSR that you are thinking of (newark) operates differently. That does just take a pot input, or variable resistance to change the high current output. Although the footprint of these SSRs looks the same, the internal circutry is very different.
From your above Wed Feb 15, 2012 6:52PM posting it appears you are confused about making a phase angle controller.
The Newark item (PSR-25) is an AC phase angle controller. The Newark PSR-25 AC phase angle controller is a ‘self-contained’ controller that only needs a potentiometer and heat sink to make a complete functional phase angle controller. The e Bay Solid State Relay (SSR) is just a solid state relay that does not contain any phase angle control and needs more additional parts to make a functional AC phase angle controller.
Suggest reviewing ‘Phase Angle Control Modules’ thread in the New Distiller Reading Lounge and look at Forum Member MuleKicker Sun Feb 12, 2012 1:30PM posting for information on building a PSR-25 based phase angle controller.
Gotcha, that makes sense. I figured it was a bit weird that they were so much cheaper and there was probably a reason for it. Thanks for the help guys!
These are just so much cheaper than the PSR-25. I would imagine that if you used the 40A one and even tried a bigger heatsink even if the parts weren't as high quality it should last a very long time. What do you guys think?
Perfect RiskyWhiskey that is exactly what I was looking for. The only thing that has me a tiny bit worried is the fact it says 470kOhm-560kOhm for the control. Does this mean you can only control it with between 470kOhm and 560kOhm resistance? But idk because that would seem a little pointless for it to only be adjustable between 90kOhms. But I guess you will know soon enough, please report the results
Is it ok to use a potentiometer rated for larger resistances? I'm guessing it just wouldn't vary the power any more if you are applying anything over 560kOhms. I found this digital potentiometer at newark that looks pretty cool. It has an adjustment rate of 3% and looks like it'd be much easier to fine tune to exactly the power you are looking for.
yes. if you get a pot closest to the rated resistance, it will have finer adjustment. you only get 1 turn, if more of that turn is over the max resistance, it wont do anything. Smaller turn of the knob= more power change Get what im saying? I may not be explaing it the best. Also, you want to make sure the wattage is good. 2w is usually what you are looking for in the psr modules
Isn't it the less resistance the more it is turned up? So shouldn't either resistor allow it to turn up all the way if I just decrease them all the way? And if I got anything over 560kOhm wouldn't it not be able to apply that high of a resistance anyways given that the relay says 470Ohm-560kOhm? But I did go for the 1Mohm anyways. I thought the digital aspect was pretty cool and should be easy to fine tune
MisterSteve124 wrote:...is the fact it says 470kOhm-560kOhm for the control. Does this mean you can only control it with between 470kOhm and 560kOhm resistance?
It means you have to use a linear potentiometer with a value between 470kOhm to 560kOhm (470,000Ω to 560,000Ω).
You shouldn't use a 100k or 220k or 1MΩ pot.
If you don't use the specified resistance you'll not be able to control the element correctly (either get all the adjustment in the first 1/2 a turn or not be able to turn the element all the way down (I'm assuming that the SSR's control cct works on higher resistance => lower output, but I could be wrong)).
You can find cheap, Chinese/Ebay, 470k pots or better quality (Bourns/Spectrol/etc) 500k pots.
EDIT: The internal control circuit is obviously designed to be used with a specified resistance so why do you want to use a higher resistance??? You'll have less control! Surely the whole point of this device is to be able to turn the element power down to maybe 750W-1000W-1500W for a column - you're gonna make life harder for yourself if you're already limited to only half a turn.
BTW you can get multi-turn potentiometers which might need three or ten full turns to achieve full resistance... not sure if you can get the required resistance/power though.
MisterSteve124 wrote:Isn't it the less resistance the more it is turned up? So shouldn't either resistor allow it to turn up all the way if I just decrease them all the way? And if I got anything over 560kOhm wouldn't it not be able to apply that high of a resistance anyways given that the relay says 470Ohm-560kOhm? But I did go for the 1Mohm anyways. I thought the digital aspect was pretty cool and should be easy to fine tune
yes, you are correct. if you put a 500k in where 560k is the spec, you wouldnt be able to turn it down all the way. more resistance = less power..
Old MacDonald wrote:EDIT: The internal control circuit is obviously designed to be used with a specified resistance so why do you want to use a higher resistance??? You'll have less control! Surely the whole point of this device is to be able to turn the element power down to maybe 750W-1000W-1500W for a column - you're gonna make life harder for yourself if you're already limited to only half a turn.
BTW you can get multi-turn potentiometers which might need three or ten full turns to achieve full resistance... not sure if you can get the required resistance/power though.
It's not that I want to use more resistance, its that I want to use a digital potentiometer, and they do not have any for 500kohms. They only have 100k and 1 Mohm. And the MegaOhm has a 3% adjustment rate vs most linear that have 10% so it will adjust finer than a 500kohm even being double the resistance.
If you wanted to use a 100k digital potentiometer, there is a pretty simple way to do it.
The SSR is asking for 470k to 560k, which is a 90k difference. If you add 470k in resistance in "series" with the 100k pot, you will have exactly what you need.
That is what I am planning on, have ordered the parts.
I think that is an awesome controller for 30 bucks. I could not build one for that if I took my time into any consideration and it would be great for controlling the electric heating element. Full power to get to boil and start the run and then reduce power to a nice calm rolling boil instead of a violent rolling boil (for reflux). Points to consider is that this controller is not going to care if it is used on 120V or 240V (600v a 40A as per spec mentioned earlier in post) as long as the wattage is not exceeded and is properly heat sunk. P=I*E Power (in watts) = I (amps) times E (volts) so for instance a 3000w element at 240v uses 12.5 amps or a 3000w element at 120v uses 25 amps. In either case the 600v 40amp triac is not outside its limitations. i may have to go check this controller out.
mrrb wrote:If you wanted to use a 100k digital potentiometer, there is a pretty simple way to do it.
The SSR is asking for 470k to 560k, which is a 90k difference. If you add 470k in resistance in "series" with the 100k pot, you will have exactly what you need.
That is what I am planning on, have ordered the parts.
That is not what the relay in question requires... Take some time to look up the manufacturers specifications sheet and you find that the reference is with regard to using a 470K - 500K pot... 250K when running 120V and 500K when running 240V... They make no mention of a 470K - 500K sweep range... And if a minimum 470 Ohms was required then simply adding a 470 Ohm resistor in series would suffice... Using 100K in place of the recommended 500K is bad advice...
Not to butt in too hard, but I have couple old blown Rockford Fosgate car amps laying around. Can I poach the outside heat sinks off of them for a router controller build?
Tough love. That is a good answer.
