Figure 4, Functional Block Diagram of the Heath Q Meter. Near the top of the diagram are two sets of test terminals, four in all. The two on the left are labeled coil. The hot terminal is positioned above the cold terminal. On the right are the external capacitor terminals. The hot terminal is above the cold one. The hot coil terminal and hot external capacitor terminal are connected together. The cold external capacitor terminal is grounded. The cold coil terminal will be delt with shortly. A block labeled oscillator has two outputs. One is connected to one end of a variable trimmer capacitor labeled Q calibration. The other end goes to the cold coil terminal. The cold coil terminal also goes through a 5 n f, 0.005 u f, capacitor to ground. The other output from the oscillator goes to a block labeled level detector. The output of the level detector goes to the cal contact of a single pole double throw switch. The other contact labeled Q is connected to the output terminal of the Q detector. The hot input of the Q detector connects to the hot coil and hot capacitor terminals mentioned earlier. The cold input of the Q detector connects to ground. The two hot test terminals connect to one side of the calibrated capacitor. The other side is grounded. The swinger of the cal - Q switch connects to one side of a meter. The other side of the meter is grounded. This completes the verbal description.
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