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Troubles making a BEAM bot (Miller engine) Answered

Hey everybody!
I'm just getting involved with the wonderful BEAM bots.
The problem is that here in Germany I don't get some of the transistors and I have to find alternatives.
Instead of the 2N3904 I use the BC546, for the 2N3906 I use the BC556 and for the MN1381 I use the TC-54.
I'm attaching the datasheets - did I get it right that I only have to "turn the BC556 around" so the pins fit?
However, I don't get the Miller engine working!

As a solar cell I use a Panasonic BP-376634 (3,4V - 30mA)

As capacitors I used different ones. The motor is a tiny cell-phone vibrating motor - I guess one of the tiniest.

As a resistor I'm using a 2.2K.

All in all I tried to follow these diagrams: http://www.solarbotics.net/library/circuits/se_t1_1381.html

I also uploaded some photos - maybe you can make out mistakes I made...

Hoping for your help!



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9 years ago

I would suggest getting some perfboard or even better a protoboard to set up your circuits. So much easier to trace your circuits if the parts are laid out neatly and reliably soldered or connected. A protoboard will let you swap out parts or correct the wiring by simply pulling it out of the socket.

I think even in simple circuits like these, substituting values of resistors and capacitors will lead to unexpected results. I am not that well versed in electronics but substituting the transistors is pretty iffy and the pin outs are specific for the function of the transistor and have to be connected that way.