Hi Gandolf.
Gandolf wrote:
Thanks, Rainbowsally, much appreciated.
Here's my first hack at a 'solution'.
555-pw-mod-rs-01-100Hz-5KHz.zip
The ramp using an adjustable current source (actual xistor in the circuit) looks good but seems to be off about 5-10 percent for what should have been 50% duty cycle so the collector of the current source is a little bit too sensitive to changes in voltage or there's a current leakage somewhere that I can't see.
Of interest to others might be
1. An example of a 555 circuit (though we don't use the output).
2. the creation of a couple of pots, one for current and the other for voltage, both only require changing one parameter and in the case of the one used for changing current the parameter is 0-1 for 0 ohms to 1 meg -- the resistor could have been any value and it would still change proportionally -- and actually, I think that was a log taper formula or something on that one.
