Page 270 - Electromechanical Devices and Components Illustrated Sourcebook

232 Electromechanical Devices & Components Illustrated Sourcebook

Item Description
B1 1.5-volt Dry Cell Battery
D1 1500 PIV Diode
J1 Banana Jumper
Test Jacks R3 X10 M1 50- _a, 1.8-k ohm, Meter
B1 X100 P1 10-k ohm Potentiometer
R2
ohms S1 R1 23 k ohm
X1 R2 300 ohm
P1 R1
R3 3 k ohm
R4 Meter Jack R4 20 k ohm
0-1 volts R5 200 k ohm
R5 + − R6 2 megohm
0-10 volts R7 20 megohm
R6 R8 9 ohm
0-100 volts M1 R9 0.09 ohm
J1
R7 R10 0.009 ohm
0-1000 volts
R11 − ohm
S1 SPDT Toggle Switch
R8
0-100 ma
R19
0-1 amp DC/Amps/Ohm
Common
R10 Jacks
0-10 amps AC
D1 R11
Selector Jacks
Figure 13-28 Bench Built Multimeter Schematic
Figure 13-29 shows a suggested layout for the front panel.
1.5-volt AA Battery
If compactness is not a concern, then increase the size to
& Holder
accommodate your personal desires. The banana selector is
made by mounting six panel jacks, as shown. The distance
3
from the center jack to each outer jack should be / of an inch. R 11 1.5 Volt
4
This spacing will allow you to use a dual banana plug as your D 1
jumper and prevent misconnection.
10-mA − + P 1
Figure 13-30 shows the back side of the finished panel. All Panel Meter R 2 & R 3
of the connections are soldered except for the meter. R and R 9 and R 10 S 1
13
R should be mounted so that there is ample clearance around
14
them, as they may get hot during normal operation. Be certain Binding R 1
to select a sturdy battery holder so that the cell is not knocked Posts
out when the finished meter is moved.
Figure 13-31 shows the case assembly. The top and bottom
panels can be plastic or laminated Masonite. The box itself is
a simple frame made from 1 inch 2 inch #1 pine boards, R 4 Through R 7 Banana Plugs
held together with drywall screws. Figure 13-30 Bench Built Multimeter Panel Wiring

Ohms DC/Amps/Ohms
- AC noninsulated Binding Post
Knob
Ground
20 30
Zero 10 40 1/8-inch Thick Metal Panel
Toggle uA 50 W/Laminated Paper Label
Switch X 10 50- µA Meter
Range X 100
Binding Post
X 1
+ 1 W/ Banana Socket
10 Places
0-100 ma Volts 10
Banana Jumper
0-1 Amp 100
(F) Banana Plug
0-10 Amps 1000
Flat Head Screw
Figure 13-29 Bench Built Multimeter Panel