on/off switch to adjustable thermal ?

[58chevy]

I do not know the correct term but I want to replace a simple on/off 3/8 toggle switch with one that I can control the temperature of heating coil. Similar to what a electric skillet would have. Have not been able to find in my little community...not sure what to search internet for or ask for at brick and morter store.....appreciate some guidence on this....dave~

[RegUS_PatOff]

it probably wouldn't be a good idea.
it would have to dissipate a lot of power.

buy a heating item that is designed to be adjusted

what is this heating coil on ? how may watts ?

[58chevy]

It is a syrup warmer in a restaurant. I do not at the moment remember the wattage..However the problem, it burns the syrup. I am beginning to understand that what I was thinking would not work and have tried to convince the owner to return the appliance and purchase one with a temperature control timer. So far that has not worked....stubborn personallity.
Thank-you for your response it was very helpful...dave~

[RegUS_PatOff]

you COULD get an ON/OFF/ON switch and make it HI/OFF/LOW by using a simple diode.

or you could just put a diode across the original switch, that would make it HI or LOW (NO OFF) unless you can turn it off some other way.

[richapplyguy]

Any type temperature control would have to have a sensor either in the liquid, or thermally bonded to the container section that holds the liquid. If there are no provisions for this, the task would be rather hard.

[58chevy]

For both of last two posts, I like the idea of the on off on switch + diode, but also adding a diode to existing switch could work well too. The unit is on 24/7, right now the temp is running at 180 degrees which is twice what is needed. What do I need to know to size the diode? Wattage still not known but rated at 10 amps...

I understand the in liquid thermo comment, why this is not incorperated in this device was my first thoughts as I learned of the problem. I was told the restaurant supply did not offer an adjustable style unit, which I thought was strange for the price they paid for this thing 160 a pop and I know at least four were purchased and possibly more. I also thought that maybe this one was defective but I was told all run the same temp...I'll try to find out more later today...

Thanks for the input...dave

[RegUS_PatOff]

or I could check the model number.

any 400v 10A (or higher) diode across the switch (either direction) will give you half the wattage.
(may be hard to find)

18 avail. on ebay .99 + $5 shipping (some kind of quantity shipping discount)

SILICON DIODE KD2011 Rectifier 400V 10A NEW (http://cgi.ebay.com/SILICON-DIODE-KD2011-Rectifier-400V-10A-NEW_W0QQitemZ290170010441QQihZ019QQ)

[RegUS_PatOff]

or if you're never going to use the HIGH wattage, you could put the diode anywhere in SERIES with the circuit. Then the switch would work as OFF/LOW.

[58chevy]

PatOff: Yesterday I found an on/off/on switch rated 110-10a 250-6a at a radio shack, this would be correct right? By series you mean to splice into wire to switch on either side? Snow emergency today here so it might be a while before I can get to this,,,drifts well over 3' so I'll be clearing snow all day.
Thanks....dave

[RegUS_PatOff]

yes, so the diode is in series with the switch.... or in one of my previous messages, just use the original switch and the diode in SERIES with it, then you'll have LOW/OFF.

but a better idea would be to change the internal thermostat...

it must have some device to turn off at a certain temperature...

if you could find that, check the temp printed on it and use a different one.

if you could post the make and model number, I may be able to find some info.

[58chevy]

RegUS_PatOff: Right I just didn't repeat that info of your previous post. I will try to find that information (M&Mn). In your last post were you saying yes to the sizing of diode as well as the splicing?? I had previously seen an adjustment screw internally 30 years ago so I thought this might have one similar to that. It does not and could not find the thermostat on this appliance. I'll look again....when I can. Tripped over a parking curb under the snow yesterday, I think I broke a rib(s), heading to the hospital.

I'll get back to you asap..Dave~

[RegUS_PatOff]

if it's 10A, that's 1200 watts, it must have some type of thermostat, maybe a slim tubular looking device. Did you find the brand and model number ?

[richapplyguy]

Pull apart your unit and check the thermostat, it must have one to regulate the temperature. Just replace it with a lower temperature thermostat.
Using a diode is a bad idea, you will not be able to regulate the temperature at all and the item will take four times as long to heat up in the morning!

[RegUS_PatOff]

half as long, half the wattage, half the power, (it's not half the voltage)

also, unit is on 24/7

still waiting for brand & model number

[richapplyguy]

Power is I squared times R. 1/2 current=1/4 power.

[RegUS_PatOff]

the current isn't half in this case....
if the voltage was half, yes, the current would be half...

a diode would remove the half of the wave-forms, which would be half of the power.

[richapplyguy]

Proof your statement, just explain why 1/2 current =1/2 power. I just proved mine, 1/2 current=1/4 power.

[RegUS_PatOff]

but it's not half the current.

a diode removes half of the waveforms

it's like turning the power on /off 50% of the time.... either every 10 minutes, every minute, every 16 milliseconds, ect....