Think about it, why would you make a vreg to go to some middle voltage, for another vreg (5v) to then also reg. How does the usb powering work, then? bypass the regulatr? They make special LDO linear vregs (low drop out) Tgeeky: and they require a few volts between input and output voltages, tgeeky. I know they heat up and basically burn on excess voltage.Ĭasper: shh, some cars can do 200mph, doesn't mean your focus can Ok, what are well known attributes of linear voltage regs, tgeeky Mrdata: so would having a resistor divider network in parallel to the PWM driver have any potential pitfalls? My brain keeps leading me to believe that the constant voltage from the network would cancel out anything lower than it coming from the driver It gives 6.20 V on my multimeter when it's connectedĮrr, when it's just connected to my multimeter If you have 12V in and 3V out and it do not become scorching hot then it is faulty Tgeeky: label facing you, pin down, pinout is in ground out Instead it doesn't power up, when connected it drops to 3V, and draws little to no current i thought this would give me a reasonable 6V power source to put into an arduino ![]() I was told combining different voltages tends to make things go Douglas Adams-type insane and assumed I shouldn't mess with itįuck me, yet another noob misunderstanding Your controller don't have an on/off pin? (or enable)Ĭasper: now how would this play along with the the PWM driver? Would the driver just "override" whatever voltage is coming from the resistor divider network? I apologize, that's how i should have initially worded it, "how would I set the standby duty to 50%" or something of the sorts. Mrdata: yes but how would I achieve that? Stanier, maybe you want 50% duty as the default then? The analog input on the controller is 5v, with 100% duty being full forward and 0% being full reverse "standby" in a servo control circuit might mean to set the motor to 0 degrees, for exampleīut to do that it has to be generating pulsesĬasper: it's to drive a motor controller over analog. I'm guessing that this is because you control a fan? there is some fan control IC that have a failsafe function If the load is quite high resistance and the pwm out can handle a voltage being applied then you can use a resistor divider network, but the pwm need to also be strong enought to make it "swing" plus the load Stanier, typically, an output might be driven low, float high, or be high impedance\ Stanier: maybe, depending on a few factors During that time, when the program has no dictation over the voltage, I need to hold the PWM channels at a certain voltage. It's going to take at least 20 seconds for the RPi to boot. Is there a way to have a "standby" voltage for a PWM circuit? I know this is subject to the IC being used to drive PWM, but it there a universal terminology for them that would mean "standby" voltage?įor example, say I am controlling the PWM driver from an RPi. Jsoft: i just wrote a python script to generate a netlist and then ran it through spice User3209:, as long as you can find a way to seal the part that you cut I would think so Will a HEPA filter stil work if I cut it to a smaller size? ![]() Too low, so i'll have to choose better cable I don't really need rasbian w/ pixel do I?ģ.8 amps going in, 28V by the end of the line ![]() I'm designing a product that would be on longass buses and i'm trying to determine cable requirements Stacked bga be compact but that seems scaryĪre you actually going to lay out 1000 ft of cable powering these things?Īlso it turns out the issue was the problem only had an imaginary answer I know i'm late to be commenting on this but not surprised they got rid of the stacked BGA MCU/RAM on the PIs what are the kind of problems one runs into with the higher speeds Jsoft: spice's solver is not very good at this problem
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