Got it. Thanks.Ron H said:I picked 20 ohms for 0.5 watt dissipation. The resistor will have 3.3v-Vce(sat), or about 3.1v across it.
R=V^2/P
R=3.1^2/0.5
R~20
There is nothing magic about 0.5w, it's just the target I've been shooting at. 62 ohms might work. You'll get about 160mw, which might be enough to heat your chip.
Actually, I did notice that. I just figured that while I was working on the post, you had edited your post. I find that some forum software doesn't always add the "Edited..." until some event happens. Either a certain amount of time passes, or the member logs off, or another member reads the post...I don't really know. I just know that if you edit your post quickly after posting it, you don't get the "Edited..." line.Ron H said:How weird. Did you notice in your post, where you quoted me, it said 160 ohms? That was the value I had given when I thought you were using 9 volts. Maybe I edited it, but there is no indication on my post that I did. Oh well.
Anyway, I'll start gathering the parts I need for this. Once again, I appreciate all the help.