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Minor
Revision made: 09/09/2002
Substituting
an LM317 for the REG1117A will work OK for a Bench Test, But it
is
"NOT A GOOD SUBSTITUTE" on the final project. It will cause
instabilities
as
the battery voltage drops to 12 volts! This will result in poor control
of
the unit and require more adjustments. Also possible, "False
readings"!
The
REG1117A is a Low Drop OUT REGULATOR. The LM317 has a 2.5 volt drop
across
it.
A
1N4148 in place of the 1N4937 will also work for short term, but will
probably
fail later. Its Too low of a current rating.
PCB
*** Make your own, or order one from me at "chemelec@hotmail.com"
R1 110 All resistors 1/4 watt.
R2 750
R3 47K
R4 47K
R5 15K
R6 4K7
R7 3K3
R8 68K
R9 4K7
R10 68K
R11 150
R12 680
R13 150
R14 680
R15 1k5 (is "J1" on the
schematic) Use for Single coil design. Do not use R16
R16 470 (is "J2" on the
schematic) Use for Dual Coil
design. Do not use R15
R17 470
R18 680
R19 10K
R20 330
R21 820
R22 47K
R23 220
R24 1K
R25 1M5
R26 51K
R27 51K
R28 2K2
R29 2K2
R30 18K
R31 8K2
R32 470K
R33 68K
VR1 25K Phier PT10V Trimpot (DC Offset for IC9) Vertical Adjust
style.
VR2 50K DC Offset for IC10 (Beep Null)
VR3 1K Volume
VR4 5K Meter Zero
C1 1 Mfd
tant. @ 35 volts
C2 10 Mfd Tant. @ 10 Volts
C3 10 Mfd. tant. @ 10
Volts
C4 10 Mfd. Tant. @ 25
Volts
C5 100 Mfd. Electrolytic @ 25
Volts
C6 1 Mfd. Tant. @
10 Volts
C7 1 Mfd. Tant. @
10 Volts
C8 10 Mfd. Tant. @ 10
Volts
C9 1 Mfd. Tant. @
10 volts
C10 1 Mfd. Tant @ 10 Volts
C11 .1 @ 63 Volts Philips Mylar Caps. MK Series
C12 .01 @ 100
Volts "
C13 .01 " "
C14 .01 " "
C15 .001 " "
C16 .01 " "
C17 .01 " "
C18 10 Mfd. Tant. @ 10 Volts
C19 220 Pf disk
C20 .01 @ 100 Volts Philips Mylar Caps. MK Series
C21 .01 " "
C22 220 Pf. Disk
C23 500 Pf. Disk
(Freq. Comp. -- May be reduced in value or omitted)
C24 500 Pf. Disk
(Freq. Comp. -- May be reduced in value or omitted)
C25 .1 @ 63
Volts Philips Mylar
C26 .1 "
C27 22 Mfd Electrolytic
C28 .1 @ 63 Volts Philips Mylar
C29 .01 @ 100
Volts "
C30 .22 "
C31 10 Mfd. Tant. @ 10 Volts
C32 Error, This Part Doesn't
exist
C33 10 Mfd. Tant. @ 10 Volts
C34 470 Mfd. Electrolytic @ 10 Volt
D1 1N4937 "High
Speed diode."
D2 1N4937 "High
Speed diode."
D3 1N4148 or 1N914
D4 1N4148 or 1N914
D5 1N4148 or 1N914
D6 1N4148 or 1N914
D7 1N4148 or 1N914
D8 1N4148 or 1N914
IC1 REG-1117A (Surface mount "SOT-223"
Package. Mounts on copper side.)
(Possible Sub.
"MC33269ST-ADJ"
"SOT-223 Package" Adjustable version.)
IC2 LT1054-CN8 -- (8 pin dip)
IC3 78L05 T0-92
IC4 79L05 T0-92
IC5 555 8 pin dip (C-mos version is acceptable)
IC6 555 8 pin dip (C-mos version is acceptable)
IC7 555 8 pin dip (C-mos version is acceptable)
IC8 555 8 pin dip (C-mos version is acceptable)
IC9 TL081 or TL071 8 pin dip
IC10 TL081 or TL071 8 pin dip
IC11 555 8 pin dip C-mos version acceptable
Q1 IRF640 (Can cut off heat tab if you wish to
reduce height.)
Q2 IRF640 (Can cut off heat tab if you wish to
reduce height.)
Q3 2SK30A or 2N3819
Q4 2N4125 PNP transistor
M1 200 Ua. Meter (or 100
Ua. or 50 Ua., But need to change R31)
For
Extreme sensitivity, use a 200 Ua. Digital Panal Meter.
SPKR Any speaker or headphones with a
"Good Low Frequency Response".
LI Aprox 40 turns,
square, round, Or Whatever! More info to Come!
L2 Same as L1 if used!
See other
Write-ups on the coils and coil forms.
BI 12 Volt, 1.2 AH
Sealed Lead Acid Battery, Or Whatever at 12 Volts!
DO NOT
operate this unit at a supply voltage of less than 11 volts
when
calibrating unit. Operating voltage must be greater than 10.5
volts, or
unit becomes unstable.
I
believe all the Semi-conductors are available from Digi-Key.
Phone:
1-800-Digi-Key
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