pwm schooling????

[mikem1977]

Hey, newbie here. Ive recently put together a generator, smack design pretty much and installed it in my truck. I think I understand the basic idea of the pwm...basicly it pulses power to the cell so its not a "constant on" so to speak which helps to keep the heat down...?am I on track here. Ive also read that some pwm's have multiple adjustments...current and Hz. I guess what im trying to figure out is if you power up your unit and set the pwm to say 15A, is that the max current it will draw even once its warmed up? The way I see it is if you control the amps you control the heat as well? As far as the Hz adjustment goes, is that how fast it cycles on and off?...ive been reading all over the net and havent found much that thouroughly explains it..so here I am:)...id like to find one that will do both if one exists, any input here? thanks for your time...Mike

[overtaker]

Welcome Mike. Someone will be around to help soon.

[H2OPWR]

Hey, newbie here. Ive recently put together a generator, smack design pretty much and installed it in my truck. I think I understand the basic idea of the pwm...basicly it pulses power to the cell so its not a "constant on" so to speak which helps to keep the heat down...?am I on track here. Ive also read that some pwm's have multiple adjustments...current and Hz. I guess what im trying to figure out is if you power up your unit and set the pwm to say 15A, is that the max current it will draw even once its warmed up? The way I see it is if you control the amps you control the heat as well? As far as the Hz adjustment goes, is that how fast it cycles on and off?...ive been reading all over the net and havent found much that thouroughly explains it..so here I am:)...id like to find one that will do both if one exists, any input here? thanks for your time...Mike

I will try to answer your questions as well as I can. Yes the PWM pulses the power to the cell to limit the amount of current your cell can draw. It produces as close as possible to a square wave as possible to instantly charge and discharge your cell. The standard PWM is simply a DC motor speed control and does nothing to stop your cell from increasing amp draw as it warms up. There are a few models out there that have a current (amperage) control built in with a feed back loop wired in (see zerofossilfuel on youtube). In my opinion they are way over priced when you simply can adjust down the duty cycle as you see your amperage climb. A simple 30 amp PWM can be bought for under $30.00 on the internet. As for Hz it is the number of times your power pulses per second. 100Hz is 100 on and off cycles per second. Some people claim that it can increase production. I am not sure either way but have my doubts. I have modified 4 PWM's so I can do tests both ways I will let everyone know the results as I get time to test. As for now my suggestion for the most economical way is to Google MX066. You will find the company that makes the PWM that 90% of E-Bay sellers are re-selling at twice the price. The company is Bakatronics. If you want to spend the extra money they also sell a frequency adjustable model but the MX066 is easily modified to be adjustable with a couple of dollars worth of parts.

[mikem1977]

Thanks for the replies! So basicly you have to mount the unit as well as an ammeter in the cab and dial the pwm down if the amps get too high? Also It appears that some pwms have hz adjustment and some dont. Id like to keep it "under the hood" as much as possible and I dont have a problem spending a few bucks if its gonna be a better more useable setup.....thanks for your replies!

[H2OPWR]

Thanks for the replies! So basicly you have to mount the unit as well as an ammeter in the cab and dial the pwm down if the amps get too high? Also It appears that some pwms have hz adjustment and some dont. Id like to keep it "under the hood" as much as possible and I dont have a problem spending a few bucks if its gonna be a better more useable setup.....thanks for your replies!

You can keep the PWM under the hood if you wish. Just remove the pot's from the PWM and keep them in the cab. Run wires from the pots to where the pots hook up to the PWM and use it that way. Just make sure the PWM is not exposed to moisture and DO NOT SEAL IT UP AS IT WILL OVERHEAT AND DIE.

[mytoyotasucks]

well im working on one that will adjust frequency, amps, and pulse.