Electric OU: Another Small Breakthrough in our Tar Baby Technology
Tar Baby needs no external bias source. All it needs is a negative 12 volt current source referred to the most negative of the running batteries. That is, something like a battery that is hooked in series with the most negative of the running batteries. The 555 voltage inverter circuit that I “designed” ( by copying it directly from a book ) works for this purpose. I didn’t have any 470 uF electrolytics so I used 2 each 220 uFs in place of each 470 uF in the circuit. I suppose you could use just about any fast diode but I have a thousand or so 1n914s in my box so every project that I use has to have at least two of them in it somewhere. Note the clear case of obfuscation: the inverter only seems to work when its own “negative” supply lead isn’t connected. That’s probably why I couldn’t get it to work properly before, and I haven’t yet had time to think about why it happens that way.