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Electronics => Beginners => Topic started by: counductivpr on June 04, 2012, 04:08:19 am

Title: switch to use with very small. battery powered, thin heater
Post by: counductivpr on June 04, 2012, 04:08:19 am
Hello all,
I have a very small thin heater I need to hook up in series to a battery and a switch.  My battery ourput is 300 Ma with a peak of 700 Ma.  Can anyone recommend a thin switch (like a momentary tactile switch) that will work like a rocker switch (remain on until pressed off)?   Since a momentary switch has to be held down to stay on, it won't work for this project.  I need the thin profile of a tacile switch, but the on/off capability of a rocker switch.  Anyway to do this with a tactile switch or other switch? 

 I know the output is a little steep for tactile switches as well.  But this is a throw away piece and the life span is very short.   
Thanks,
   
Title: Re: switch to use with very small. battery powered, thin heater
Post by: ftransform on June 04, 2012, 04:53:23 am
mind telling me what kind of thin heater you are using? I was actually looking for something like this... the best I could come up with is to snake around with nichrome..
kinda curious about your project too.. defogging optics perhaps?
Title: Re: switch to use with very small. battery powered, thin heater
Post by: amyk on June 04, 2012, 08:48:15 am
You surely mean 300 to 700mA, right? Several hundred million amps isn't easy to switch :o

A relay and a tiny 6-pin MCU might work better, that way your switch doesn't need to see the full current and it can still be momentary.
Title: Re: switch to use with very small. battery powered, thin heater
Post by: metalphreak on June 04, 2012, 02:38:48 pm
You can get clicky switches like the ones in generic PC cases (except not momentary). These ones are only rated for 500mA though:

http://www.ebay.com.au/itm/10pcs-8-x-8mm-Capped-Knob-Self-Lock-Push-Tactile-Switch-/150820358058?pt=AU_B_I_Electrical_Test_Equipment&hash=item231d9807aa#ht_2194wt_1142 (http://www.ebay.com.au/itm/10pcs-8-x-8mm-Capped-Knob-Self-Lock-Push-Tactile-Switch-/150820358058?pt=AU_B_I_Electrical_Test_Equipment&hash=item231d9807aa#ht_2194wt_1142)
Title: Re: switch to use with very small. battery powered, thin heater
Post by: G7PSK on June 04, 2012, 04:56:41 pm
If it is a throwaway unit it would not matter if the switch is over run it would likely last long enough anyway.
Title: Re: switch to use with very small. battery powered, thin heater
Post by: Time on June 04, 2012, 05:11:35 pm
Should be very easy to find such a switch.  Watch Daves videos that explain how to do parametric searches with Digikey, Mouser, and the likes.
Title: Re: switch to use with very small. battery powered, thin heater
Post by: mariush on June 04, 2012, 05:17:13 pm
You mean something like this?

http://www.digikey.com/product-detail/en/CUS-12TB/563-1102-6-ND/1124240 (http://www.digikey.com/product-detail/en/CUS-12TB/563-1102-6-ND/1124240)

(http://media.digikey.com/photos/Copal%20Photos/CUS-12TB_sml.jpg)

http://www.digikey.com/product-detail/en/MLL1200S/450-1577-ND/1201378 (http://www.digikey.com/product-detail/en/MLL1200S/450-1577-ND/1201378)

(http://media.digikey.com/photos/Tyco%20Alcoswitch%20Photos/MLL1200S_sml.jpg)

Plenty of similar switches like this on Digikey...
Title: Re: switch to use with very small. battery powered, thin heater
Post by: counductivpr on June 04, 2012, 08:09:45 pm
Thanks for all the replies.
Yes the output of the battery is mA.  I got the heater from an aeronautical engineering firm to test for a project I'm working on.  If they say I can release the name of the manufacturer, I'll reply and let you know.  Thanks for all of the switch information.  I'll make some purchases and get to work.
Best,