Some Q's

moordenaar · Joined: Nov 09, 2010 Posts: 16 Location: beep

A bunch of noob questions for you. Sorry

Unused inputs - 100 k to gnd?

Outputs - LED how? Also how do i calculate the resistance for say 20 mA LED, running chip at 5-9 V. Also is the signal going out of CMOS chip same as input / VSS? Also what about the voltage drop across the LED?

Also I think I read something about 1N4148 / 1N914's used for something allround somewhere, but for what?

tjookum · Posted: Wed Nov 10, 2010 10:08 am Post subject:

Noob or not, asking questions and finding answers is the best way to learn.

rich decibels · Posted: Wed Nov 10, 2010 2:43 pm Post subject:

Sometimes you can slap an LED on an output gate and it works, but sometimes it interferes with the signal in an unhelpful way, in which case you can use the circuit from Experiment 4 on this page: http://www.beavisaudio.com/Projects/CMOS_Synthesizers/

stolenfat · Posted: Wed Nov 10, 2010 11:45 pm Post subject:

maybe not such a good thing to throw towards a newbie.. but as mentioned before in previous threads, LEDs can often affect the sound and can be utilized at FILTERS. heyo

moordenaar · Joined: Nov 09, 2010 Posts: 16 Location: beep

You underestimate me stolenfat Cool

I think I understand the "experiment 4"

LED is connected to Vcc of CMOS chip. R1 is the current limiting resistor of LED. Transistor is doing the switching. 1N4148 diode is protecting emitter out of transistor. Capacitor is smoothing the output ?