Subassembly Pretest

To conduct a test on the device, follow these steps:

1 Turn pots counterclockwise and install eight fresh A A batteries into the BH1 holder, as shown in Figure 27-5.

Note that a variable bench supply capable of 12 volts-direct current (vdc) at 1 amp with a volt and current meter can be a great conven­ience for the remaining steps and for the test­ing of other similar circuits.

Subassembly Pretest

Cut out center of two 3.5" plastic caps by placing them on the enclosure tube and cutting out the center section with an x-acto knife using the inner wall as a guide.

Drill hole in handle for pushbutton switch S1 It may be necessary to recess the hole so nut will reach shank

Note that hole in EN1 for handle is best cut with a 1 g" circle saw Fit must be tight to properly secure handle in place The handle serves as the housing for the single 9 volt or 8 AA cells

HAND1

Panel is cut from аз|х 3^" piece of 035 aluminum Cut согпеге to approach a circular shape.

Subassembly Pretest

Front Panel Fab

Figure 27-5 Final blowup

2. Push button SI and note a loud, piercing wave coming from TD1. Measure a current of 300 to 400 milliamperes in a series with a batter}’.

3. Rotate R9 and note that the frequency increases to above the audible range. Then measure a current of 100 to 200 milliamperes.

4. Note the wave shapes shown in Figure 27-2 for those who have a scope.

5 Turn on sweep control R2/S2 and note the fre­quency being modulated by a changing rate as this control is adjusted. Use caution as certain sweep rates may cause epileptic fits and other undesirable effects. Sweep rates between 7 and 20 per second should be used with cau­tion.

Final Rssembly

The final steps arc as follows:

1. Cut the rear panel from а З’Аі – x 3V4-inch piece of aluminum. Add holes for the controls as shown in Figure 27-5.

2. Create the CAP2 and CAP3 retaining caps from a 3]/2-inch plastic cap. This is easily done by placing a cap over the end of the main enclosure and carefully removing the center section with a sharp knife, using the wall thickncss as a guide. These reworked caps now retain the transducer and the rear panel to the main enclosure.

3. Create EN1 and HA1 from the material indi­cated on the parts list. Add a hole in the main enclosure for the insertion of the HA1 handle section. The hole must provide a tight fit. Glue the parts together.

4. Create the final assembly as shown.

Note that the frequency range with the values shown is 4 to 20 kFlz. The frequency range can be changed by increasing the value of C5 to lower it or by decreasing the range to raise it. Experiment for a desired result. The sweep range with the value shown is 4 to 50 Hz. C2 can be changed in a similar function.

Sound pressure measurements will vary from 130 to 100 db at 18 inches depending on the frequency. Certain sweep rates between 5 to 20 per second may cause dizziness or epileptic fits.

Subassembly Pretest

Table 27-1 Phaser pain field gun project parts

Ret # Qty Description DB#

R1,6,8,12 4 IK. ‘/i-watt resistor (br-blk-red)

R2/S2 500K to 1 meg pot/swiich, 17 millimeters

R3 2.2K. ‘/«-wait resislor (red-red-red)

R4.5 2 I OK.’ M-watt resistor (br-Ы k-or)

R7 10-ohm,1A-watt resistor (br-blk-blk)

R9 ЮК pot. 17 millimeters

RIO 5K trimpot, horizonia I

R13 1 30-ohm, З-wall resistors (or-Wk – blk)

С1,4 2 .01 mfd/50-volt disk capacitor (103)

C3 t0() mfd/25-voll vertical electrolytic capacitor

C2 10 mfd/Z^-voll vertical electrolytic capacitor

C5 .01 mfd/50-vull polyester capacitor

Г6 1000 mfd/25-volt vertical electrolytic capacitor

C8 .01 mfd/2 Kv disk capacitor

C9

L2.3 2 1 millihenry inductors in place of RlS and Rl6,as marked on PCB 1UIMH

LI Inductor—2 Hitachi 30.48 E cores and mating bobbin, as shown in Figure 27-4 (UPPPl LI

Q1 PN2907 PNP GP transistor

Q2 IRF530 or 540 N channel metal-oxide-semiconductor field effect transistors

(MOSFETs)

Table 27-1 Cnntinued

Ref. # Qty. Description QB#

IC1,2 2 555 DIP timer

HS [ Heatsink bracket shown in Figure 27-4

SW1/NUT 6-32 X ’A-inch screw and nut

CLl 1 9-volt battery clip

BH1 Eight A A cell holders for 1.5 volt batteries (В 1)

SI SPST pushbutton switch

PCPPP1 PCB or use perforated vector board

IUPCSONIC

TD1 Polarized 130 db piezo transducer

IUMOTRAN

WR1 3 feet #24 vinyl hookup wire, red and black piece

WR2 5 feet #24 magnet wire to wind Ll

САРІ 17/«-inch plastic cap (A11Ы)

CAP2,3 2 3 V2-inch plastic cap (A3 xh ), as shown in Figure 27-5

RPl 3 ‘/s-inch square #22-24 aluminum, as shown in Figure 27-5

EN1 3 ‘/2- OD X 7-inch PVC tube, as shown in Figure 27-5

HANDl 1 7/s – OD X 6-inch PVC tube, as shown in Figure 27-5

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