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anmolt
12th July 2005, 15:05
Got the FET driver to work finally...conveting DC to AC using switches...Supply is set at 12V...Getting really confused trying to work out the relation between Inductance and Energy....say i need 10W power...using the formula Energy= .5 L i^2..........and i have abt 3A flowing through the wire...this gives me a value of 2H odd..........isnt this figure a bit too high???should i be using P=VI=Li(di/dt)..instead or is this for instantaneous power??my core is made of silver steel which has low permeability.....so cant even use another core..length over which i can wind is abt 2.5 cms odd........options quite limited.........

Hitcher
12th July 2005, 16:30
Check your hydrocillator settings first.

pete376403
13th July 2005, 10:11
O the topic of electronics - how difficult would it be to make a 12V DC to 24 V DC converter that could supply about 4-5 amps continuously.
I have a one-piece flying suit that is wired for heating but is 24v. Has a hood and glove and boot liners, all with heating elements, that attach to press studs on the wrists and ankles, zipped pockets everywhere. I've used it while riding and its good as far as it goes (crash abrasion resistance would be very low) but it would be nice to get the heating part working. Bought from Surplustronics about 10 years ago, brand new. (Although there was a label inside that said "Repacked at Portmouth 1953"!)

zadok
13th July 2005, 10:34
Got the FET driver to work finally...conveting DC to AC using switches...Supply is set at 12V...Getting really confused trying to work out the relation between Inductance and Energy....say i need 10W power...using the formula Energy= .5 L i^2..........and i have abt 3A flowing through the wire...this gives me a value of 2H odd..........isnt this figure a bit too high???should i be using P=VI=Li(di/dt)..instead or is this for instantaneous power??my core is made of silver steel which has low permeability.....so cant even use another core..length over which i can wind is abt 2.5 cms odd........options quite limited.........
What the!? I'm just a dumb screw.

Pixie
14th July 2005, 01:37
O the topic of electronics - how difficult would it be to make a 12V DC to 24 V DC converter that could supply about 4-5 amps continuously.
I have a one-piece flying suit that is wired for heating but is 24v. Has a hood and glove and boot liners, all with heating elements, that attach to press studs on the wrists and ankles, zipped pockets everywhere. I've used it while riding and its good as far as it goes (crash abrasion resistance would be very low) but it would be nice to get the heating part working. Bought from Surplustronics about 10 years ago, brand new. (Although there was a label inside that said "Repacked at Portmouth 1953"!)
Have you tried it on 12V?
It'll draw less current but it may be sufficient.

pete376403
14th July 2005, 12:09
Yes I did try it on 12v, it was possible to detect a tiny bit of heat but nothing like what I was hoping for (I've got a thing about riding to Central Otago during mid winter)

I did have a 12-24v converter (since lost) which was made for me by a guy at IBM but it used some specialised IBM bits and I can't duplicate it.

I do know I need an invertor (to make the 12v DC into an AC voltage, then a transformer to get it to 24V. Do I need a rectifier to get it back to DC or would heating run ok on AC?

dhunt
14th July 2005, 12:33
Yes I did try it on 12v, it was possible to detect a tiny bit of heat but nothing like what I was hoping for (I've got a thing about riding to Central Otago during mid winter)

I did have a 12-24v converter (since lost) which was made for me by a guy at IBM but it used some specialised IBM bits and I can't duplicate it.

I do know I need an invertor (to make the 12v DC into an AC voltage, then a transformer to get it to 24V. Do I need a rectifier to get it back to DC or would heating run ok on AC?
Actually what you want is a dc to dc converter. Which what you want. I'm sure there some available on the market. what sort of current draw does your heater use?