Variable AC control (low cost)

restrictions prohibit wood fired BBQs) from a stove top. Problem is that sometimes, 1500W is too much and I need to throttle back the temp.

stove but can't find anything local. A new one is in the 70-bucks range and that can't happen.:)

opening and closing a vent to let heat escape as cooking times can often be in the ten to twelve hour range.

that with 1500W? I am using that in the smoker now, but it does not get quite hot enough so that control is always on max.

A series diode would cut the power in half. Or an industrial/restaurant size light dimmer, the kind with heat sink fins. ebay?

Ceiling fans don't use much power. Figure that anything that will work will have heat sinking, except a bimetal type.

--

John Larkin         Highland Technology, Inc

jlarkin at highlandtechnology dot com
http://www.highlandtechnology.com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom laser drivers and controllers
Photonics and fiberoptic TTL data links
VME thermocouple, LVDT, synchro   acquisition and simulation

Thanks John, I will see what I can find. The diode would not help as that w= ould drop it below the 1000W adjustable I am currently using. I guess I nee= d to be adjustable from 1000W to 1500W as the 1000W cooks some stuff fine, = but not enough grunt for large chunks of brisket etc that need crisping up.

Dave

A series diode would cut the power by 1/4.

would drop it below the 1000W adjustable I am currently using. I guess I n= eed to be adjustable from 1000W to 1500W as the 1000W cooks some stuff fine= , but not enough grunt for large chunks of brisket etc that need crisping u= p.

Series droppers would probably be your simplest cheapest bet. Preferably L or C, but R will also work.

NT

restrictions prohibit wood fired BBQs) from a stove top. Problem is that s= ometimes, 1500W is too much and I need to throttle back the temp.

c stove but can't find anything local. A new one is in the 70-bucks range a= nd that can't happen.:)

be opening and closing a vent to let heat escape as cooking times can ofte= n be in the ten to twelve hour range.

I use that with 1500W? I am using that in the smoker now, but it does not g= et quite hot enough so that control is always on max.

Maybe a big variac? I've got one that does 10 Amps... Paging through Mcmaster Carr (happens to be open on my desk) I see that a 15 amp unit is ~$400 new... maybe ebay?

George H.

sometimes,

stove

can't

the

that

enough

Two things.

1. Are you sure your element is 110V? All the electric stoves I'm familiar with are 220/240V. Or is it from a tabletop style hot plate?
2. As for the control, find a used stove (not a hotplate) and scavenge the control(s) from it. Art

Huh. Every stovetop (as opposed to hotplate) element I've ever seen is

220V. The only 110V part of any electric stove I've ever dealt with is the clock and convenience outlet (if present.)

Not hardly. No where near the power handling required.

It might work, for a while. Unless it's marked with higher ratings than a 1000W element requires (quite possible, if it's even marked at all), it will probably die fairly soon if it's being asked to switch 150% of its rated load. If it's a 2000W item that's been switching 1000W, it won't mind 1500W - so it depends on what it is.

If you are up for a bit of electronics, solid state relays are available on ebay for not much scratch (think I paid $15 for 2 the last time I bit) if you shop carefully, and get one with the right inputs/outputs - then you can do proportional control with some not too fancy electronics (so the relay is off 100 out of 100 cycles, or on 100 out of 100 cycles, or on 97 out of 100 cycles, or 73 out of 100 cycles, or 682 out of 1000 cycles, or whatever you like...) SSRs work nicely for this since they don't really mind being switched every few seconds. Depending how you go about it the whole thing could be cheap or expensive, and the control circuit could be simple and manual or fancy and thermostatic.

A 15 amp variac will also work, but they are rarely found cheaply.

If you don't mind dealing with the rest of the old electric stove, complete, often working, rarely clean ones show up in the free section of craigslist with some regularity, at least around here. The oven part might let you build an even better smoker...

--
Cats, coffee, chocolate...vices to live by
Please don't feed the trolls. Killfile and ignore them so they will go away.

restrictions prohibit wood fired BBQs) from a stove top. Problem is that sometimes, 1500W is too much and I need to throttle back the temp.

Look for a heavy duty dimmer.

--
Failure does not prove something is impossible, failure simply
indicates you are not using the right tools...
nico@nctdevpuntnl (punt=.)
--------------------------------------------------------------

restrictions prohibit wood fired BBQs) from a stove top. Problem is that sometimes, 1500W is too much and I need to throttle back the temp.

stove but can't find anything local. A new one is in the 70-bucks range and that can't happen.:)

--
No.

Please explain that.

--

John Larkin         Highland Technology, Inc

jlarkin at highlandtechnology dot com
http://www.highlandtechnology.com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom laser drivers and controllers
Photonics and fiberoptic TTL data links
VME thermocouple, LVDT, synchro   acquisition and simulation

An autotransformer might work, to subtract (or even boost!) some volts from the heater.

120v full power

120-6 90%

120-12 81%

diode 50%

--

John Larkin         Highland Technology, Inc

jlarkin at highlandtechnology dot com
http://www.highlandtechnology.com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom laser drivers and controllers
Photonics and fiberoptic TTL data links
VME thermocouple, LVDT, synchro   acquisition and simulation

1/2 the voltage, 1/2 the current = 1/4 the power.

--
Let's say we connect a 100 VAC 1Hz source across a 100 ohm resistive
load for one second.

Then, during the time the source is positive going, the load will be
dissipating the same power as when the source is negative going.

Placing a diode in series with the load will prevent either the
positive going or negative going signal from entering the load,
resulting in its dissipating only half the power it would if both
halves of the signal were there.

--
But it's not half the voltage or half the current, it's half the time.

The diode cuts the voltage by half. 50 % duty cycle for voltage. The current will fall by half in a resistive load. P=IxE P=I / 2 * E / 2 P=(I*E)/4 Power will be one forth of what it would be at 120 volts.

Better pay attention. The Johns are correct.

What is 1kW 50% of the time?

Confucius, he say: "When man find himself in hole, first thing is to stop digging."

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510
845-480-2058

hobbs at electrooptical dot net
http://electrooptical.net

OMG, I can't believe I'm reading this here.

Ok, if you put a diode in series with a 100 watt bulb fed from 120 volts AC, what is the RMS voltage across the lamp? What is the RMS current through the bulb? What is the power dissipated in the bulb?