Radio Control: Electrics
THE MODIFIED Astro DC/DC Super Charger-still more! The article on modifying this charger, which appeared in the September and October 1987 issues, continues to bring in reader response. This month there's one common problem and one frequent question to discuss. Some readers have experienced a peculiar form of operation with their modified chargers wherein the charger seems to work OK with the HI/LO switch set to HI-but won't work at all in the LO setting. It turns out that these folks got the transistor in the circuit 180º wrong. Admittedly, the lead arrangement on some of the recommended transistor options is easy to confuse, and so some readers accidentally got the collector and emitter interchanged but had the base connected correctly. This "rotation" just happens to put the transistor in the so-called "inverted mode," and some transistors can actually function-a little-which explains the "almost right" charger operation.
