11-APR-2001
Late at night, as usual, not even in the lab yet! I'm messing around on the kitchen counter...
(These pic's might be too big for decent page loading speed, let me know if it is to much of a hog, est. 196 sec. at 28kb)
11-APR-2001
Late at night, as usual, not even in the lab yet! I'm messing around on the
kitchen counter...
(These pic's might be too big for decent page loading speed, let me know if it is to much of a hog, est. 196 sec. at
28kb)
| OK, as stated, just seeing what I can see. On left, the mess. On right, the trace of a pulse coming from the 555 timer circuit. The yellow input lead is connected to the + from battery (4 AA cells) and the green lead is connected to the output from the 555 (pin 3) via a small capacitor. |
 |
 |
| Here I added a ferrite core coil (choke?), passing the signal from the
capacitor thru the coil to the Vdd (+). My green lead is connected between the cap and the
coil. Again, just to see what happens. What do you see? |
 |
 |
| OK, now I swapped the coil for a transformer (2-coil, was 1:1 but about
half the windings removed from one, also the ferrite around the sides broke off - oops.)
Connection is the same as above, secondary is open. Look at that dip after the pulse! |
 |
 |
| Now this is weird! I connected the green lead to one end of the secondary coil, the other end still 'open'. What
do you think of this? |
 |
 |
| Now I connect the 'open' secondary to the Vdd (+), really different, eh? |  |
 |
| This time connect other end of secondary coil to Vss (-) instead of
Vdd(+). Looks about the same to me. |
 |
 |
| DIFFERENT CIRCUIT: "Dual LED flasher" (see below) Very stable, equal length pulses. Scope shows one output, the other is the opposite. Didn't try a coil on it yet, next time... |
 |
 |
| Dual LED flasher: Uses one 4011, a Quad 2-input NAND Gate. Very nice output. |
 |
|