<html><body><div style="color:#000; background-color:#fff; font-family:bookman old style, new york, times, serif;font-size:12pt"><div><span>Thanks a lot, I will get through that and get back to you both. I'm rather worried about creating too much Noise at the discuss, after all I'm now in Korea so not "physical" part of the community, hopefully I will be able to join the crowd soon, I'm missing the people mostly.</span></div><div><span><br></span></div><div><span>Sincerely,</span></div><div> </div><div>Frantisek Algoldor Apfelbeck<br><br></div><div>biotechnologist&kvasir and hacker</div><br><br><div>http://www.frantisekapfelbeck.org</div><div><br><br></div><div>"There is no way to peace, peace is the way." Ghandi<br><br> <div style="font-family: 'bookman old style', 'new york', times, serif; font-size: 12pt; "> <div style="font-family: 'times new roman', 'new york', times, serif; font-size: 12pt; "> <div dir="ltr"> <font size="2" face="Arial">
<hr size="1"> <b><span style="font-weight:bold;">From:</span></b> Henner Zeller <h.zeller@acm.org><br> <b><span style="font-weight: bold;">To:</span></b> sean.p.cusack@gmail.com <br><b><span style="font-weight: bold;">Cc:</span></b> Frantisek Apfelbeck <algoldor@yahoo.com>; Noisebridge <noisebridge-discuss@lists.noisebridge.net> <br> <b><span style="font-weight: bold;">Sent:</span></b> Friday, August 17, 2012 3:33 PM<br> <b><span style="font-weight: bold;">Subject:</span></b> Re: [Noisebridge-discuss] recommendations for discuss forum - electronics<br> </font> </div> <br>
On 16 August 2012 22:37, Sean Cusack <<a ymailto="mailto:sean.p.cusack@gmail.com" href="mailto:sean.p.cusack@gmail.com">sean.p.cusack@gmail.com</a>> wrote:<br>> I'd say this forum isn't a bad one :). 1-2 day response time could be<br>> optimistic or conservative depending on your question!<br>><br>> Do you need the peltier to be able to be heated and cooled? If this is a<br>> requirement, you want to use an H-bridge instead of a relay. An H-bridge<br>> will let you flip the polarity of the DC current, thus being able to flip<br>> which side of your peltier is hot or cold. Also, an H-bridge is a way to<br>> sort of PWM big power stuff...without the pulsing. So, if you want control<br>> to be adjustable, you should really use an H-bridge. The relay will just get<br>> you off or on.<br><br>Also, a relais is mechanical, which means (a) it wears out (b) the<br>clicking will drive you crazy. Unless you get a solid state
relay,<br>that is.<br><br>+1 to the H-bridge suggestion if you need heating/cooling.<br><br>If you just need one direction, and switching 12V, a FET with a low<br>Gate-Source voltage will do the job, e.g.<br>http://www.digikey.com/product-search/en/discrete-semiconductor-products/fets-single/1376381?k=irfz44n<br>The 'low' Gate Source voltage means that it switches with the ~ 5V of<br>our Arduino (traditionally, FETs were more happy with voltages around<br>10V, but these here go down to ~4V).<br>This solution of course means that you share a ground with both circuits.<br><br>Also: if you actually only want heating, no cooling, then you might<br>consider just a cheap resistive heater, not a peltier element. You can<br>even operate them on 120V, if you use a solid state relay. That relay<br>is a bit more expensive (~$20, but you find cheaper ones (~$5) on<br>eBay), but you save the bulky PSU.<br><br>If you want a nice precise temperature control, you might
want to<br>implement a PID controller to quickly reach your temperature and stay<br>within narrow ranges. But speaking of which, you can directly get<br>these in a bundle with solid state relays for relatively cheap ( e.g.<br>http://www.ebay.com/itm/Universal-Digital-PID-Temperature-Controller-TD4-SNR-Solid-state-relay-SSR-40DA-/130697313612?pt=LH_DefaultDomain_0&hash=item1e6e2abd4c#ht_2088wt_1398<br>) (people use this kind of stuff for sous vide cooking).<br><br>(the main problem on asking on this list is that you might get more<br>answers to your question than you were bargaining for ... :) ).<br><br>-h<br><br>><br>> Hope that helps!<br>> Sean<br>><br>> On Thu, Aug 16, 2012 at 1:49 AM, Frantisek Apfelbeck <<a ymailto="mailto:algoldor@yahoo.com" href="mailto:algoldor@yahoo.com">algoldor@yahoo.com</a>><br>> wrote:<br>>><br>>> Hi to all,<br>>> I would like to ask for a recommendations for some discus forum
where I<br>>> can ask questions related to electronics with focus on arduino controlled 5<br>>> V and higher voltage circuits and sensors. When I encouter some issues I<br>>> would be hoping to get answers/suggestions preferably within one or two<br>>> days.<br>>><br>>> I’m quite beginner so I have a lots of questions when I’m building the<br>>> experimental incubator, so now I’m for example looking for a type of relay<br>>> which I could directly switch on by arduino (5v DC) and it would be strong<br>>> enough to switch on off peltier device of +- 100W (power coming from PSU<br>>> 300W so 12v DC). This is just one of many things which I need to find out<br>>> and sometimes searching for the solutions by myself takes just ages.<br>>><br>>> Many thanks,<br>>><br>>> Sincerely,<br>>><br>>> Frantisek Algoldor Apfelbeck<br>>><br>>> PS This
may be answer to the question but I would rather like to confirm<br>>> it<br>>><br>>><br>>> http://www.amazon.com/AGT-Power-Relay-250VAC-Type/dp/B008G1HLRA/ref=sr_1_1?ie=UTF8&qid=1345106766&sr=8-1&keywords=5v+dc+relay<br>>><br>>> biotechnologist&kvasir and hacker<br>>><br>>><br>>> http://www.frantisekapfelbeck.org<br>>><br>>><br>>> "There is no way to peace, peace is the way." Ghandi<br>>><br>>> _______________________________________________<br>>> Noisebridge-discuss mailing list<br>>> <a ymailto="mailto:Noisebridge-discuss@lists.noisebridge.net" href="mailto:Noisebridge-discuss@lists.noisebridge.net">Noisebridge-discuss@lists.noisebridge.net</a><br>>> <a href="https://www.noisebridge.net/mailman/listinfo/noisebridge-discuss"
target="_blank">https://www.noisebridge.net/mailman/listinfo/noisebridge-discuss</a><br>>><br>><br>><br>> _______________________________________________<br>> Noisebridge-discuss mailing list<br>> <a ymailto="mailto:Noisebridge-discuss@lists.noisebridge.net" href="mailto:Noisebridge-discuss@lists.noisebridge.net">Noisebridge-discuss@lists.noisebridge.net</a><br>> <a href="https://www.noisebridge.net/mailman/listinfo/noisebridge-discuss" target="_blank">https://www.noisebridge.net/mailman/listinfo/noisebridge-discuss</a><br>><br><br><br> </div> </div> </div></div></body></html>