Before I plug this circuit into my PC, I'd like
to know if it's going to blow things up.
I'd like to use a 9v battery to power it,
rather than a 5v supply, since I'm using spare
parts for this. Can I use 9 volts and 1k
resistors, rather than the 5v and 330 ohms I've
seen in schematics? I know the current won't
blow the LEDs, but will the 9v cause problems
for the port circuitry? Are PC ports active
pull-up, or open-collector devices?
Re: Help Getting Started - Simple DC Circuit ... >> (I apologize for posting this basic circuit question.... >> the switches will be closed and all 30 LEDs will be glowing. ... >> unplug the battery, as the machine is ok once all the switches are closed. ... (sci.electronics.basics)
Re: Astable Multivibrator help! ... In order to guarantee oscillation, you need to add a diode logic OR function which provides base drive only if one OR the other of the transistors is OFF, like shown below, a lock-up cannot occur because there will be insufficient base drive. ... Oddly, with the two diodes, it takes the circuit about 20 seconds to start up. ... the circuit will fire the LEDs up immediately and start the alternation in one or two seconds. ... Even at 9V, which I assume means an alkaline battery that will spend most of its time in the 7.2-8.4V range, you have the caps charging to ... (sci.electronics.design)
Re: Simplest current regulator ...circuit, but I need help to use it in something simpler. ... that would go into the collector of the Vbe-setting transistor,... sinking roughly 300mA from the battery via the white LED. ... I wouldn't like to drive even these LEDs from a voltage source - the ... (sci.electronics.design)
Re: thoughts and direction on this LED circuit idea ... > clusters with 10-20 leds per. ... > randomly within the cluster and after some time will stop ... Operating from a battery puts more limitations on your circuit.... (sci.electronics.basics)
Re: multi-led hi-side constant-current question ... >> current to several LED's with 1 CC circuit,... > and use a single current limiting resistor for the LEDs.... I need constant current to get adequate LED drive for battery... 10m away)the important issues are LED brightness and good battery ... (sci.electronics.design)
