Digital electric controller

[papapro]

why do not use diode and the switch across the diode. When you want full power of 1500 W close switch with switch open you will have 1/2 cycle and power on half.
It depends what watage are the elements, I would use double aperage diode for the heater.And heat sink, if you need schematic I can post it but I need the details of heaters.

[rad14701]

why do not use diode and the switch across the diode. When you want full power of 1500 W close switch with switch open you will have 1/2 cycle and power on half.
It depends what watage are the elements, I would use double aperage diode for the heater.And heat sink, if you need schematic I can post it but I need the details of heaters.

This method would only produce 1/4 the power, not 1/2... Ohms Law at work... You're cutting the voltage in half while the resistance remains the same... For example, a 240V 5500W element only produces 1375W when only 120V is applied and that is what using a diode effectively does... Therefore your only two power settings would be 100% or 25% power...

[Johnny6]

Actual Rad, the power should be 1/2. The diode doesn't cut the voltage in half, but it only conducts half of the time. During the portion of the waveform the diode is conducting, the heating is 100%, during the other half of the waveform, the heat is off. The average power comes out to 50%.

[papapro]

Rad why are you so negative about my comments. read my comment 3 times before you answer the same I do with your comments. I deal with this shit every day this is my bread for over 50 years.
Read up about the diodes how they work in this case load is all the time the same
the only when using diode voltage stays the same the only half cycle is passed through the diode.

Regards PapaPro

[rad14701]

Rad why are you so negative about my comments. read my comment 3 times before you answer the same I do with your comments. I deal with this shit every day this is my bread for over 50 years.
Read up about the diodes how they work in this case load is all the time the same
the only when using diode voltage stays the same the only half cycle is passed through the diode.

Regards PapaPro

That would depend on the diode... You never specified the exact diode you were referring to as far as breakover voltage, etc... A generic statement about using a diode is very vague in the grand scheme of things as I'm sure you would agree given your experience... The same goes for Johnny6...

Edited to add: It also depends on whether you are running one or two hots (120V vs 240V)...

And, papapro, don't take my comments so personally... I had no clue what you do for a living... I know what I do, but not what you do... But this is neither the time nor the place for pissing matches... Next time give the whole answer rather than just saying you can toss in a diode...

[papapro]

a diode is a diode is a diode .....this is semiconductor which conducts electrical current ONLY ONE WAY. You are mistakenly probably thinking of ether SCR or a triac which both can control voltage. Diodes some time are called rectifier to produce DC voltage. In project I suggested I simply pointed the absolute easy way to send 1/2 cycle to the load.

" Next time give the whole answer rather than just saying you can toss in a diode..."

I am a busy man that is why i tossed the idea and mention if he needs I can help with the drawings ETC, Please read my first comment.
PapaPro

[papapro]

why do not use diode and the switch across the diode. When you want full power of 1500 W close switch with switch open you will have 1/2 cycle and power on half.
It depends what watage are the elements, I would use double aperage diode for the heater.And heat sink, if you need schematic I can post it but I need the details of heaters.

I looked for you Rad

[rad14701]

I am a busy man that is why i tossed the idea and mention if he needs I can help with the drawings ETC,

I am also a busy man so I guess we are all guilty of not providing enough information at times...

I've made several diode based controllers over the years, but at lower power ratings than what we use in this hobby... I also build triac based controllers that use a bridge rectifier for hysterisis-free operation...

[shadylane]

why do not use diode and the switch across the diode. When you want full power of 1500 W close switch with switch open you will have 1/2 cycle and power on half.
It depends what watage are the elements, I would use double aperage diode for the heater.And heat sink, if you need schematic I can post it but I need the details of heaters.

Here's a link that has info on the type of controller your describing
http://www.allaboutcircuits.com/textboo ... -circuits/" onclick="window.open(this.href);return false;" rel="nofollow
Figured I'd throw this in, to spoon feed Rad some education

[rad14701]

Figured I'd throw this in, to spoon feed Rad some education

[papapro]

Thanks Shadylane nice link the only my point would be that they show spdt switch
in my comment I would use on/of switch which is cheaper. Regular household switch cost a buck and 3way buck fifty. And would do the same thing.

I think we should help each other not fight.ask why ,how.
PapaPro

[shadylane]

Similar to what your describing
Many of us use a on/of switch to bypass the SSVR
That way it doesn't have to carry the current when the controller is wide open

[Johnny6]

[quote="rad14701"] The same goes for Johnny6...
[quote]

Got no skin in this game. Just trying to help. Tapping out.

[shadylane]

Figured I'd throw this in, to spoon feed Rad some education

New members have questions, old farts such as you and me are supposed to answer the questions.
If you can't answer without being mean, then being quiet is probably the best option.
My apologies to all the members

[papapro]

Shadylane you do not need to appologize Why we start new topic as electrical and electronic questions to be answered I am in to help young members.

[Flintstone]

+1

Sent from my VS985 4G using Tapatalk

[Kegg_jam]

Wow, who'd a thunk the lowly diode would be so controversial.

Had this whole long paragraph typed in but decided to hit the backspace on it because after reading it back, I sounded like a dick.

So, sure you can use a diode to half the duty cycle but that's probably not terribly useful.

Continuous control is where it's at. The smoother the better.