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Kind of a 6 of one half dozen of the other situation. and who wants to burn perfectly good parts anyway.
A charge pump is a type of DC-DC converter that uses capacitance instead of inductance to control output voltage. They are limited in output power compared to an inductive converter because of the difference between an inductor and a capacitor. To try to use terms simple as possible, it's the difference between current flowing through a wire coil and charge building up on a set of plates. Current flowing through a wire coil is going to be much less limited in terms of power. The advantage is charge pumps are simple devices and easy to employ.The charge pump simply boosts voltage so the MOSFET can be driven with a higher voltage than what's available from the battery. This puts the MOSFET in a lower resistance on-state and removes the requirement to use MOSFETs with extra low gate-source threshold. It really frees up the range of MOSFETs that can be used, but also adds more parts. Kind of a 6 of one half dozen of the other situation.For any current path the limitation is going to be heat. If the current paths on PCB heat up to much that can be a problem as much as MOSFETs overheating themselves. The current paths he's using on the PCB are pretty ample so I imagine the MOSFET would overheat before the PCB traces would. Can't say for sure without torture testing it, but the current tolerances are so high it would not be easy to build a test rig for that, and who wants to burn perfectly good parts anyway.
Looks good! Which mosfet did you decide on?Got some new boards assembled:
David, did you pull the board with the fuses?
Were you trying to make a board with a p-channel and voltage detector?
Nice! Looks like you've got plenty of solder on the traces. I think I fired that board for 4 minutes continuous and it barely even rose in temperature.
Another thing I noticed was my DMM picking up 0.0407v @ the 510 connection at rest... im guessing there is some voltage leakage / idle drain?
Emex gr8 job bu I think your resistor is 1k not 10k 1002 is usually 1k 1003 is 10k may be wrong but on my 4 digit smd's thats how it is..
What's the voltage on the gates at rest?I'm pretty sure 1002 is 100 with 2 extra zeros = 10k
What's the voltage on the gates at rest?
Battery / Input Voltage = 4.17vGate @ Rest = 4.17v (measured from battery Positive to Gate)510 @ Rest = 0.0488v (with minor fluctuations)510 @ fire (no atty / load) = 4.17vIs that normal?
Im ordering your 555 board David as soon as ya say its golden which I may have missed the post, but if its golden ya-- gonna poss. put it in a aa 2s box mod, it will fit perfectly per specs and look awesome..
510 @ Rest = 0.0488v (with minor fluctuations)
Man... cramming the fused TriParaMos into a 1590G is proving to be a challenge...I feel like I should just use the 1590B and call it a day.
Schematic only at the moment.Thanks Craig for the part recommendations throughout this thread.Pfets: SI7157DP-T1-GE3Voltage Detector: TPS3700Low voltage cutoff ~3vIt's quite possible I've fucked something up, but this is what I have so far.