I bought a DCDC Boost Converter from ebay, it worked well, but the design was flawed for my uses as the input and outputs were on the same side, yes I did short output + and - and I probably messed up the output fet. It worked well, I attached a 12V fan to cool the dcdc down.
I tried my best to copy the circuit and couldn't, but figured there has got to be a simpler way. The chargers output is 4-8A (measured) 19.50V and I require 20.50V to the batteries.
I ran into one problem with using the charger by itself. It would shut down when I connected the battery. I had an old coil resistance heating element to calm the rush of current down enough to start the charging process. I would then bypass the resistance after a few moments hooked up to it. Different resistances would give me various current. One inch would be mA. and shorter pieces would achieve higher amps.
I attached one circuit diagram that perhaps could help me, I have not tried it because its 50W. It brought me back to the same question, there has got to be a simpler way, but if those are the total amount of components I require to achieve my simple goal, then it is no problem for me to buy them and solder them up.
The wait for the dcdc from China, along with the Canada Post strike will be at a minimum a month or two.
Any help would be appreciated. I know there are some dcdc on ebay that have cc / cv control, but my laptop chargers achieve those modes. I would prefer each pos and neg from input and output to be on every corner, so my DMM probes dont slip off and break the dcdc.
I use this charger everyday to charge up my mobility batteries. I can get by with 19.50V from the charger, but that extra 1.00V would help in being able to go longer distances per charge.
Thanks for your time in reading this.
My probe touched both inputs, so cap, fet, or smt.
Both gnds are common.
It seems so simple, on the top view. Then when I get to around IC chip I get lost trying to find the traces. The cap seems good with my contiuity probes, the Input fet is all open no matter what combo I do.Unlike the output fet. So I will unsolder, look at the markings and buy a few. I am sorry I lost the paper work I have done on my progress for the circuit diagram for this dcdc. To improve on the design of this dcdc, if the fet fix works, is to put the red pos on both in and out right on the + of each cap.
That 8 pin IC is a UC843A
http://andyscarpets.info/uc3843a-20/
Quote - The UCA/UCA are fixed PWM controller for Off-. Line and DC to DC converter applications. The internal cir- cuits include UVLO, low start up current. Optimized for Off-line and DC to DC. Converters. •. Low Start Up Current (
Input Power Mosfet is 80NF70 G640KTFT
https://www.st.com/en/power-transistors/stp80nf70.html
Just a random circuit I found, has nothing to do with the dcdc above. I was hoping to copy it and apply it, but I think its just better to copy the QSKJ dcdc I bought on ebay and just lay it out differently.
I tried my best to copy the circuit and couldn't, but figured there has got to be a simpler way. The chargers output is 4-8A (measured) 19.50V and I require 20.50V to the batteries.
I ran into one problem with using the charger by itself. It would shut down when I connected the battery. I had an old coil resistance heating element to calm the rush of current down enough to start the charging process. I would then bypass the resistance after a few moments hooked up to it. Different resistances would give me various current. One inch would be mA. and shorter pieces would achieve higher amps.
I attached one circuit diagram that perhaps could help me, I have not tried it because its 50W. It brought me back to the same question, there has got to be a simpler way, but if those are the total amount of components I require to achieve my simple goal, then it is no problem for me to buy them and solder them up.
The wait for the dcdc from China, along with the Canada Post strike will be at a minimum a month or two.
Any help would be appreciated. I know there are some dcdc on ebay that have cc / cv control, but my laptop chargers achieve those modes. I would prefer each pos and neg from input and output to be on every corner, so my DMM probes dont slip off and break the dcdc.
I use this charger everyday to charge up my mobility batteries. I can get by with 19.50V from the charger, but that extra 1.00V would help in being able to go longer distances per charge.
Thanks for your time in reading this.
My probe touched both inputs, so cap, fet, or smt.
Both gnds are common.
It seems so simple, on the top view. Then when I get to around IC chip I get lost trying to find the traces. The cap seems good with my contiuity probes, the Input fet is all open no matter what combo I do.Unlike the output fet. So I will unsolder, look at the markings and buy a few. I am sorry I lost the paper work I have done on my progress for the circuit diagram for this dcdc. To improve on the design of this dcdc, if the fet fix works, is to put the red pos on both in and out right on the + of each cap.
That 8 pin IC is a UC843A
http://andyscarpets.info/uc3843a-20/
Quote - The UCA/UCA are fixed PWM controller for Off-. Line and DC to DC converter applications. The internal cir- cuits include UVLO, low start up current. Optimized for Off-line and DC to DC. Converters. •. Low Start Up Current (
Input Power Mosfet is 80NF70 G640KTFT
https://www.st.com/en/power-transistors/stp80nf70.html
Just a random circuit I found, has nothing to do with the dcdc above. I was hoping to copy it and apply it, but I think its just better to copy the QSKJ dcdc I bought on ebay and just lay it out differently.
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