.. 1 meg. in series with 470k) R6 39 k R7 33 k R8 100 ohm C1 0.047 uF (not critical) C2 30 pF (or more) trimmer C3 100 uF, 10 volt or more Q1 2N4403 (substitution risky) Q2 MPS-A18 (substitution probably won't work) Q3 MPS-A56 (sub may work - ...
.. This circuit will power a 6 inch 4 Watt fluorescent tube off a 12 Volt supply, consuming 300 mA. It may also be powered by a suitably rated universal AC/DC adapter. Advantages of the ...
.. close values are OK although the values shown are quite common. The 1 uF capacitor may be just about any type, with a 16 volt aluminum electrolytic being the most likely choice. The capacitor will see about 1/2 volt reverse bias at times ...
.. to the other transistor base and reverse the meter leads. If the voltage on the 2.2k resistors isn't low, maybe under a volt, try cleaning everything with a solvent and thoroughly drying it. Once the reading is low and steady, hold a ...
.. on the dynamic conductance of optoisolators' junctions, simple optoisolator bridges compute the watts and volt-amperes of an ac load. W Stephen Woodward, Chapel Hill A decade or so ago, I designed a simple circuit that ...
.. or a super-regenerative detector feeding a dynamic earpiece through an impedance transformer. The power supply is a 9 Volt battery and the telescopic antenna contains a base loading coil. The switching did intimidate me a bit. While not ...
.. above whatever voltage is on pin 2. Since pin 2 is generally connected to ground - the 7805 is usually referred to as a 5-volt regulator. However, R1, C1 Z1 hold pin 2 at 9v1. Therefore the output at pin 3 will be ( 9v1 + 5 = 14v1 ). ...
.. from the threading process! This isn't exactly the easy way to build such a pen but it gets the idea across. A tiny 10 A 9 Volt alkaline battery was installed and the threaded nylon bushing was tightened. A little clear epoxy fills the LED ...
.. and connect the wires to the inside of the MP3 player’s Play button. Replace the transformer with the nine-volt DC wall adapter. Connect the five-volt voltage regulator’s input to the adapter, and attach its outputs to ...
.. batteries are the scourge of cellphone jockeys and iPod people everywhere. But you can avoid volt loss by charging your gadgets while you carry them. Just equip an old messenger bag with a lightweight, ...