hi, im not making much progress on this so i ask for help.
i dont have access to many parts so please go with what i have!
i need to urgently build a laptop charger to supply 9.5 volts @2-5 Amp from 11-15 volt input.
it must be stable through this range of input.
i have only one 555 timer, 2x 2n3055 a bag of small npn transistors, resisters capacitors and a 741 op amp, icl7612, max660, and a few basic cmos logic chips.
the circuit needs to be simple as possible, and tough as nails. i tried a design using a lm317t driving the 3055's in paralel but the 317 cant handle the dropout and output voltage drops on load.
i think the best way is to use the 555as a pwm chopper but i dont know how to realise that with feedback and some kind of reference.
a linear dropper might do, but pwm would be more efficient, my power comes from small solar panels and old car batteries and i dont want to waste a watt as heat if i can avoid it.
so i invite suggestions of circuit diagrams to do this job with the parts on hand, bear in mind that i cant get other stuff and dont live in a place its easy to get stuff. i only have a basic test meter.
thanks i look forward to hearing ideas.
i dont have access to many parts so please go with what i have!
i need to urgently build a laptop charger to supply 9.5 volts @2-5 Amp from 11-15 volt input.
it must be stable through this range of input.
i have only one 555 timer, 2x 2n3055 a bag of small npn transistors, resisters capacitors and a 741 op amp, icl7612, max660, and a few basic cmos logic chips.
the circuit needs to be simple as possible, and tough as nails. i tried a design using a lm317t driving the 3055's in paralel but the 317 cant handle the dropout and output voltage drops on load.
i think the best way is to use the 555as a pwm chopper but i dont know how to realise that with feedback and some kind of reference.
a linear dropper might do, but pwm would be more efficient, my power comes from small solar panels and old car batteries and i dont want to waste a watt as heat if i can avoid it.
so i invite suggestions of circuit diagrams to do this job with the parts on hand, bear in mind that i cant get other stuff and dont live in a place its easy to get stuff. i only have a basic test meter.
thanks i look forward to hearing ideas.