light bulb connected to serial port

Hello. Just for an experiment, I want to connect a light bulb to a serial port and make it turn on and off with intervals and I want to use the pyserial library for this. Could anyone give me some suggestions please?

a serial port has enough power to operate a LED (light emitting diode) with no external power source needed, if you need more light than that how much do you need?

if pyserial supports toggling the DTR or RTS lines of the serial port they could be connected to the LED via a 1K resistor, (connect the other LED terminal to SG)

larger lamps can be controlled by using the serial port to operate some sort of electrically operated switch... if you need details ask.

Bye. Jasen

Transitions on the serial port are fast enough, even at 110 Baud (assuming your port will even go down that low), that the persistence of a light bulb's filament will make it appear that the bulb either stays on continuously or barely flickers at all.

If you're serious about doing this, it's much easier to just plug an RS232 breakout box (with LEDs, of course) onto the serial port, connect pin 2 to pin 3, cut the port down to its lowest available speed, and fire away with a Fox or similar test pattern.

I will add that I don't really see the point of doing this experiment, outside of illustrating that there is some sort of activity going on. What, exactly, are you trying to demonstrate or accomplish?

Happy tweaking in any case...

I do not know electronics very well, so I will ask my friend about this. What do you mean by a 1K resistor? Is this the universal name for what you are talking about?

I find electronics very interesting, and thought this experiment quite suitable and cheap for a first experiment.

fairly universal, the full name would be "one kilo ohm resistor, one quatrter watt, 5 percent tolerance "

typically looks something like this

---{#####}--- with coloured bands. red,black,red,,gold ( , is a gap ,, is a wider gap )

Its purpose is to stop too much electricity from flowing through the LED and burning it out, typical serial ports won't destroy a typiical LED rapidly. you could leave the resistor out if you only intend to use the led ocasionally.

you

For a 1k resistor this should be : brown,black,red,,gold ( , is a gap ,, is a wider gap )

--DF