Heat blanket help

[infinityskis]

AfteR reading a ton on how to make your own heat blanket I still had a few questions.1 why do you need one dimmer per blanket 2 and instead of dimmers could I just use a PID controller. Thanks

[amidnightproject]

I believe you need the dimmer because the PID won't regulate the amount of power going to the blanket. It'll only flip a relay on/off.

someone will correct me if I'm wrong however. I believe the homemade blanket thread explains it as well.

[MontuckyMadman]

I think i need a dimmer.

[chrismp]

amidnightproject is right. you need the dimmers to limit the amount of watts running through the blanket so it doesn't burn up. the cheapest way to achieve this is using dimmers.
i use two because it's hard to find dimmers powerful enough to get enough amps for two blankets, plus in my case it's the only way i have to regulate the temperature since i don't use PID controllers (my resin takes 20min to cure, so i'm okay with monitoring the process during the whole pressing time)

[infinityskis]

but chrismp i have only 120v outlet so would one dimmer be enough to control the wattage in my house. \

cause those dimmers are like 60 $

[sir.orange]

but chrismp i have only 120v outlet so would one dimmer be enough to control the wattage in my house. \

cause those dimmers are like 60 $

couple of europe builders (including me) are using a fairly prized power controller from "kemo", this one: http://www.kemo-electronic.de/en/Light- ... 000-VA.php
works also with 120v... if you re not in europe you ll find a power controller similar to this one from other companys, definetly

[chrismp]

you should be happy that those dimmers are so cheap...regulating the wattage for resistive loads is so much cheaper than trying to regulate the voltage (your second option).
a transformer built to take such loads is very hard to find and costs a fortune.

i know a cheap PID will work too, but i'm just not that confident with letting my diy heat blankets draw all the power they want. the resistance wire is rated to something around 600°C which is way beyond what the silicone can take.

so if you're aiming for cheap controls with a diy heat blanket, definitely go with dimmers. PIDs are a liability in this case. using both in combination is fine though.

[infinityskis]

wait so I can use dimmers instead of pids

[chrismp]

you can if you're okay with babysitting the temperature until the epoxy is cured. dimmers alone offer no sort of automation. you just set the power supplied to the blankets with a potentiometer and watch the temperature on a thermometer (i got one from ebay with two thermocouples for 20 bucks). but i'm totally fine with watching over the temps it since my boards are in the press for only half an hour.

[infinityskis]

also shrimp if I use the KEMO dimmer will it work with an american plugs and such

[infinityskis]

sorry i meant chrismp not shrimp

[chrismp]

haha, no worries! it's rated for 110-240v. thats the important part...doesn't matter what type of plug you use. just make sure the cable is thick enough for the power you're putting through.

[MadRussian]

but chrismp i have only 120v outlet so would one dimmer be enough to control the wattage in my house. \

cause those dimmers are like 60 $

this probably will work it rated for 15 A


http://www.harborfreight.com/router-spe ... 43060.html

[chrismp]

wow, that's cheap...looks like it could work. i'm just wondering what the principle behind this is. looks too small for a dimmer that powerful.

edit: i found out how it works. it just chops off parts of the AC current. conlusion is, this should work. i have two blankets running at 1000w each tops. with this controller you can go up to 1650w which is plenty for one blanket.

[infinityskis]

Hey chrimp or others how what did you use for the lean wire in the heat blanket



I found this wire that was for tool repair and it had one end striped and on with a plug. but the only thing I is I don't know were to put the grounding wire on the cord into the blanket