T&L Publications

I ran across commercially available "BatteryMINDer" chargers that seem similar to what you guys are discussing. You might find their ad interesting.<p>The ad is in Northern Tool and Equipment catalog number 1502 on page 112.<p>Northern has a web address: NorthernTool.com<p>These chargers h...

RonH:<p>Thanks for your circuit, Ron. It will take a bit of study (possibly including your recommended control theory, new to me) to understand what the differences are between our approachs and why mine oscillates and yours does not.<p>The dif amp oscillator does have it's points, but just now it l...

RonH:<p>Ron, my sympathies. I think we may have lost yitiger as a customer.<p>Nevertheless, I'm glad to have met you and had a chance to work with you on an interesting project.<p>I promised a schematic of your latest Dif Amp Oscillator version to play with on your simulator program. <p>This version...

RonH:<p>The circuit shown above is consistent with yitiger's battery under charge location and 24 volt power supply as charger requirements.<p>It should be usable with the battery either in or out of his car. I think.<p>This circuit is isolated from the rest of the world so we are free to recognize ...

RonH:<p>Thanks for your reply. The oscillator does still seem worth playing with. For instance I found a way of adjusting duty cycle over a wide range including 50%. I promise I will come up with a schematic for your simulator input.<p>But, I moved back to the original problem of yitiger's 0-2A batt...

RonH:<p>Congratulations! You are the proud father of a 10khz oscillator!<p>1)It has about a 60% duty cycle (60% "ON" time). 2)It oscillates between 0A and a max of 2.6A. 3)It is self-starting and reliable. 4)The transition times on and off are about 10 microseconds. 5)It is sweetly well be...

RonH:<p>After sleeping on the comparison of build with simulation notion I discover that it wouldn't be too tragic if the predicted 65khz oscillation does occur with the build:<p>This would be a self-starting oscillator capable of reliable operation while a LOT of power is being extracted from it co...

RonH:<p>Thanks for your fascinating reply suggesting a comparison of an actual circuit build performance against a circuit simulation performance.<p>I am setup to build and test a 0-2A battery charger by the conceptual scheme shown in the last drawing.<p>If I did build it and give you accurate and c...

RonH:<p>Congratulations! You are my first literary critic as an electronics writer wannabee.<p>I've built a number of circuits like this and haven't smoked one yet. It's a smoothie.<p>In any case, this is a tiny circuit with 9 parts, not counting the battery, and costs me less than two dollars to bu...

http://paralleltransistors.com/drawings/ed-18_gif.gif <p>yigiter:<p>I got lucky and found my notes on difference amps.<p>Here is a detailed drawing adapting a difference amp to your circuit.<p>The LM324 comes with four opamps on the chip. I'm using two of them as you see.<p>I think this will work i...

RonH:<p>NICE drawing!

yigiter:<p>Yes. The equation for current through Rsense is I = Vin / Re. <p>Re is Rsense.<p>The difference amp I have in mind does not amplify the voltage across Re nor does it diminish it. So the current control circuit operates the same way as does the simple version.<p>Somewhere in my notes, I ha...

http://paralleltransistors.com/drawings/ed-17_gif.gif <p>yigiter:<p>There is a way to build a current regulator with your load grounded and control circuit related to ground.<p>It uses a difference amplifier like that in Forest Mims' Engineer's Mini-notebook Op Amp IC circuits. Except:<p>1)Use LM32...

yigiter:<p>If I understand your last post:<p>1) you are trying to build a 12V (adjustable current) battery charger.<p>2) you have a 24V source separate from this 12V battery.<p>3) you do not have a transformer input electronic power supply (isolated) to work with here.<p>Is the 12V battery mounted a...

<p>yigiter:<p>I've done a drawing for you, trying to make more
clear that an isolated power supply can make it
possible to put the current regulator anywhere
in your load circuit.<p>Do you know what an isolated power supply is?