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The Regulator
There are two pieces of new test equipment that have to be tested out first to see if they work. The first is the power regulator which will supply the excitation current to the alternators rotor. In review, the regulator is a voltage following power transistor which uses a small line powered power supply as its reference voltage. That power supply has switch selectable settings which make it easy to use compared to a variable output supply. The first test it has to go through is the traditional 'smoke test'. It has been radically rewired with many parts added. The resistance is first measured across the plug to make sure it is not a dead short. I then plugged it in and 'ta Ra.' - no smoke. It passed. The 'Power OK' neon light works.
The second test is to put a small resistor (1k) across the output to see if it functions. This test requires a DC power input also. A 9 volt battery is used instead of a car battery. If there is a problem with the power supply the 9 volt battery will become overloaded and fail to deliver power. If a car battery had been used instead it would cause far more serious damage due to its high power delivery ability. The output is measured and found to be ok up to the 9 volt setting. The ammeter is found to be wired backwards. Oops! The output at the 9 volt setting is about 8 volts. That is correct because there is a voltage drop across the power transistor. The settings are only numbers now and do not represent the output value from the regulator. The test has sort of passed. The ammeter leads need to be reversed. No harm done. The other 'Power OK' light works good at 9 volts. The yellow 'Output Active' and the green 'Output Indicator' LEDs also work ok even at 9 volts. They are 12 volt LED units.
The third test for the regulator is to use a heavy load and a car battery as the DC supply. The car battery has had a 15 amp fuse and a on/off switch added to it. These are mounted on a piece of 1x2 wood which also serves as a terminal board and handle for the battery. Safety is the main reason for this. If there is an electrical problem during an experiment the car battery will 1) burn it up, 2) blow it up, and then 3) explode. They are quite dangerous. The switch adds to the safety of any experiments and is very convenient too. The metal contact straps are fastened to the battery terminal posts using small band clamps.
A 10 ohm power resistor is chosen for the load. It should dissipate up to 14.4 watts (12v square / 10ohms). It is rated at 10 watts but may be used in this way briefly. All connections are made and the switches are turned on. Nothing came out. "WHAT!" says I. The ammeter on the regulator shows an increasing load at each setting and yet no voltage is delivered to the load. Several meters are added and they show that only the small power supply is delivering power to the load through the power transistors base circuit. No amperage is coming from the battery. The small power supply is to weak to develop a voltage across a 10 ohm load. It did burn out the .25 amp fuse at 350ma and then a .5 amp fuse at a reading off of the scale. The scale is 500ma maximum.
The power transistor is determined to be faulty and gets replaced. The same results are repeated. The power transistor needs more drive power than the small power supply can deliver. The optional transistors shown in the schematic are added to the circuit. These are 4 small signal transistors wired in parallel with each other so that they function as a medium power transistor. Adding them to the power transistor makes a Darlington pair of 5 transistors. The test is repeated and this time it works ok. The load resistor gets hot quickly at the upper settings. The regulator is now working ok. The regulator meter shows no reading at full scale output.
Another discovery is then made. When the battery switch is turned off the fuse blew out again. Without the power from the battery the power transistor had nothing to send to the load. The small power supply was left to power the load all by itself through the bases of the transistors. The battery switch has to be turned on first and off last. If the battery starts to go dead during a test a reading will begin to show on the regulators meter. This will happen because the small power supply will have to add more of its own power which will no longer be coming from the battery. The fuse will blow if the problem is not stopped. A .25 amp fuse will be quite adequate for the regulator.
The BoomBox & The PowerMouse
The second new piece of test equipment to test is the BoomBox. The BoomBox is basically just a power relay in a box. It is made to do several types of experiments with. Most of those experiments amount to connecting things to the power lines, hence the name BoomBox. The PowerMouse is basically the switch to control the BoomBox with.
There are two completely separate circuits here. The only thing they have in common is the power relay. The purpose is to isolate the test power from the control power & the operator. Both circuits may be used at several voltages independent of each other. The voltages of 12Vdc, 120Vac, 240Vac may be used as well as other voltages above and below, which are likely to be produced by exotic generator tests. The power relay may be a 12Vdc or a 120 Vac unit. Both use the same socket. The PowerMouse has a switch to select 12Vdc or 120 Vac operation of the control circuit. The two sockets of the outlet are wired in series, not parallel as usual.
The original idea came from a magazine article in the early 70's. It was a device to make magnets with. The device was merely a small coil of wire in series with a switch and a circuit breaker. The polarity of the magnet could not be predicted. It depended on which phase the AC line power was in when the switch was thrown. A rack of power diodes that plugs into the series socket makes that predictable. Another experiment it may be used for is to determine the proper size of a glass plate limiting capacitor so that a 12 volt ignition coil may be powered directly from the wall outlet without burning out.
The most obvious use for the BoomBox is to do 'smoke tests' with. This is particularly important if capacitors are involved. Capacitors explode like bombs when overloaded. That's why the PowerMouse has so many switches and lights. It also has a long extension cord which can be used as a stereo extension cord as well. The transmitter may send a large amount of RF energy back to its power source if it is faulty. A small (small) degree of safety is added by using this device for it as well.
The grounds for the two circuits may be tied together or kept separate by the screw in the middle of the outlet. The outlet is mounted on rubber faucet washers inside the box. When a 3 phase alternator is used as a 2 phase generator the midpoint ground is not neutral the way it is for split phase 60 cycle AC. That midpoint ground will present full voltage every 3rd phase. That's why the grounds are made to be separatable.
The two green neon lights on the box are to indicate that the relay is ok after a test is made. An inductor has a tendency to burn the points as they separate but a capacitor has a tendency to weld them shut when they close. Burned points tend to weld together easily also. They lights are supposed to remain off if that happens. They are not foolproof. They are only one more little bit of added safety. They will not function at all for 12 volt power tests.
The circuit breakers are designed for 120 & 240 Vac. They will hopefully work at lower & higher voltages and for DC. The amperage that they trip at will probably be different then. Future testing will determine that. Do not use slide switches as DPDT switches for power circuits. They short the two power lines together momentarily as they slide.
Before actual testing of the BoomBox the plugs are measured to see if there is a direct short inside the box. Ok so far. Finally the moment of truth has come. It's time for the actual test. When it comes to testing power circuits I'm a devout coward and I wear heavy rubber gloves. The inside of the box is crammed full of wires. It started out as a simple idea, but it grew quite a bit along the way. The control circuit is tested first. The clicking relay tells me that part is ok. The power side is connected. The relay clicks again, no smoke yet. The shunt plug and a drill are plugged into the test outlet. It works ok.
One of the green 'Point OK' neon lights is working ok the other remains dark. That happened because I had only used a 2 wire extension cord for testing. A grounded 3 wire cord is required for both lights to operate properly. When the 120/240 switch is in the 240 position they both flicker because they are at ½ voltage. The BoomBox has passed the test. The 3 wire cord was not used because for this test I wanted to see if the metal box was electrically hot using a meter.
