2x 2N3906 or equivalent
4x 2N3904 or equivalent
2x 47K resistor
Some equivalents are the 2N2222/2N2907 or the BC639/BC640 combination.
Here's how to freeform your own H-bridge:
BEWARE! THE CONNECTIONS YOU MAKE ARE VERY TINY, SO CHECK REGULARLY FOR SOLDER BRIDGES BETWEEN LEADS. CHECK IF THE SOLDERED LEADS ARE IN GOOD CONTACT.
Glue two 2N3904's and one 2N3906 together n a smooth surface.
Make two of these, and glue together as shown
Now solder the outer leads together so they make a nice flat "bridge"
Also bend the third lead on the oute transistors down as shown. Bend them nice and tight along the surface of the transistors.
Make cross links as shown, by trimming the second leads and bending the other lesd over. Solder and trim. Be aware that the links don't touch eachother, by making one link higher than the other. I use a knife to make sure there is space left.
Now make a second pair of bridges parallel to eachother. Beware not to touch the downbent lead.
Trim the middle leads to about 5mm.
Bend the rear pair of downbent leads to touch the front ones. Solder and trim.
Trim one side of the resistors to about 2mm and solder onto the middle leads.
Now yer finished. If it doesn't work the first time, don't give up! these little suckers can be a real pain in the ass.
-The most front bridge is the "+"
-The most rear bridge is"-"
-The downbent leads are "out"
-The untrimmed leads of the resistors are "in"
If using the BC639/BC640 combination the layout looks like shown below:
Connections remain the same (resistors are input, middle pins of outer transistors output, upper two negative, lower two positive.
JOINING THE H-BRIDGE AND THE BICORExxr
