by JMACgyver » Wed Jan 02, 2013 7:31 pm
Welcome!
I tried posting a reply last year for you, but a reload problem with the site lost it in the ether.
Rather than explain it all again, here is the parts placement and solder connections drawing I put together.
(Limited explanation follows)
That doodad at the end of X2-2 is an NPN Transistor, which is basically an electronic switch. It lets a little voltage/current switch a larger voltage/current to a device or component. In your schematic, the arrow (emitter) end is connected to Ground, and the non-arrow (Collector) end is connected to the Relay K1 that you want to switch on & off. The voltage coming from the PWM signal goes to the center leg (Base - but not always the "center" pin; check your part specs carefully) and when that voltage is present, it allows the transistor to conduct between the Emitter and Collector, thus completing the circuit that turns on the relay. When the voltage is not present, the transistor is not conducting, and the relay switches off.
Now, in my diagram, i put in K1 in a generic pin configuration. check the pinout of whatever relay you do use to wire it correctly. Normally (but not always) the two parallel end pins are the coil, which receives the voltage. the other three pins (or more) are the common (C), Normally-Open (NO), and Normally-Closed (NC) pins. i brought all three out to a header so you can choose whichever suits your needs.
The yellow lines are your parts leads and/or jumper wires; the red dots are your solder joints to the parts.
If your prefer RadioShack parts, I would invest in a breadbaord kit, and a breadboard PCB so that once you wire it up to test it, you can directly transfer the parts and jumpers to the circuit board and make it permanent.
Post again with any questions, and I'm sure Pebe or I will be glad to help.
--Electro--
aka The Other David
- Attachments
-

- A modified version of the James PCB photo
- david_172b.jpg (420.66 KiB) Viewed 4151 times
"In Theory, the is no difference between practice and theory. In Practice, there is."