Construction

The Body Detector is built up on two pieces of strip-board each having 18 holes by 34 cooper strips. We start construction with board A. This holds the regulated power supply, the digital mixers (IC3), the inverter and the relay.  Details of the topside component layout together with the underside details are shown in figure above. All components should fit into place without difficulty, provided that miniature radial capacitors are used. 

 

Commence construction by cutting a standard piece of strip-board down to size using a hacksaw. Create the breaks in the underside of the strip-board with a handheld drill bit or other appropriate tool. Solder in position the wire links and solder pins, then the dual-in-line socket, then the resistors, the relay and the diodes continuing with the capacitors, transistors and voltage regulator IC4. The polarity of the piezoelectric sounder WD1 is unimportant. 

Be careful to observe the correct polarity of the electrolytic capacitors and the correct orientation of the regulator, the transistor, diodes, L.E.D, relay and IC3. Pin 1 and IC3 lies close to a small indentation on one end of the encapsulation. The cathode (k) of L.E.D D1 has the shortest lead and the cathodes (k) of diodes D2 and D3 are banded.

Prepare seventeen sheathed wires 15cm long- eight of which are colour-coded. The colour-coded wires attach to the oscillator board (board B) later. Solder wires to Mode switch S1, power socket SK1 (power in), jack socket SK2 (out), L.E.D. D1 and two solder tags which each attach to a Test bolt as shown. Finally attach the leads from S1, SK1, SK2,D1 and the test bolts to the topside of the strip-board and connect the colour-coded wires to the solder pins as indicated in figure 7. 

Check that all the wire links and components are correctly in place. Check that the track breaks are all there and in the correct positions. and that there are no solder bridges on the board. The author routinely runs a thin, sharp screwdriver down between all the strip-board tracks.