Deer Repellent/ Seismic Sensor

Here is a simple sensor which can detect the seismic vibrations caused by a person or
large animal walking nearby. A representative application for the sensor is a deer
repellent for the vegetable garden. When a deer steps near the sensor a loud buzzer or
beeper sounds for a few seconds startling the would-be vegetable thief away. The
sensor also makes an effective intruder detector to catch trespassers as soon as they
step on the property!


The unit is designed to consume minute amounts of power when not rattling to provide
many months of unattended protection (practically set by the battery shelf life). The
seismic sensor is built from an ordinary 2 inch speaker by gluing a mass to the speaker
cone to lower its resonance frequency. A lid from a baby food jar with a little extra
weight glued to the inside will work fine.

The CA3094 I.C. is an unusual op-amp consisting of a programmable transconductance
amplifier connected to a darlington transistor. In this circuit the darlington is combined
with a pnp transistor to form a monostable timer which determines how long the buzzer
sounds. When the ground shakes, the vibration sensing speaker generates a small voltage
which is amplified causing the voltage on pin 1 to go high. The darlington in the IC and
the 2N4403 turn on with regenerative feedback provided by the diode. The 2N4401 turns
on, powering the buzzer until the monostable resets.

The circuit may be used to activate a variety of devices including a relay to control line
voltage devices, a transmitter to telemeter an alarm from a remote location, a battery powered walkway light, or even one of those battery powered squirt guns! The output
transistor may be replaced with a power darlington transistor for directly controlling
higher current loads.

The circuit may be built into ordinary plumbing PVC pipe or practically any
weatherproof enclosure. A larger detection area may be accomplished by burying a long
pole or PVC pipe just below the surface of the ground with the seismic sensor located
above the pole. Vibrations will readily travel down the pole whenever a footstep occurs
anywhere along its length.

The seismic sensor may be replaced with other sensors for different applications. A
photocell/ resistor divider will sense changes in light level, a microphone will sense fairly
low sound levels, and a diode detector will sense a low-level RF field.

Deer Repellent/ Seismic Sensor

Noise Gate

The parts for this Noise Gate are:
J1 - J2: 1/4 INCH MONO FEMALE CHASIS MOUNTING JACKS
C1 - C5: 0.1 MICROFARAD CERAMIC DISC CAPACITORS AT 50V
P1: 10k POTENTIOMETER
P2: 100M POTENTIOMETER
R1: 1K RESISTOR
R2: 100K RESISTOR
IC1: 741 OP AMP

HF / VHF / UHF Active Antenna

R1 = 1 Mega Ohm
R2 = 220K
R3,R6 = 100K
R4 = 100 ohm
R5 = 10K potentiometer, (pc mount)
C1,C2,C5,C6 = 0.01microF, ceramic disc
C3 = 100pF ceramic disc
C4 = 4.7 to 10microF, 16WVDC, radial lead electrolytic
B1 = 9-volt alkaline battery
S1,S2 = DPDT PC mount pushbutton switch
J1,J2 = PC mount RCA jack
 ANT1 = Telescoping whip antenna (screw mount)
 MISC = PCB materials, enclosure, enclosure, battery holder and connector,
        wire, solder, etc.

Circuit will expand the district, 3-30Mhz = area high-frequency (HF), 3-300Mhz = areavery-high frequency (VHF), 300-3000MHz district ultra-high (UHF) frequency.
Select Allow a Dog When SW 1-a to the amplifier Q1 = a district. high-frequency (HF).
Select Allow a Dog When SW 1-a to the amplifier Q2 = a district. high-frequency (HF)area, and very-high frequency (VHF).
R5 = adjust the gain of the circuit SW2-a, b ON-OFF signal expansion.

PCB

ADD - ON STEREO CHANNEL SELECTOR by PRABHASH K.P.

The add-on to the circuit presented here is useful for stereo systems.
This Circuit provided for connection Stereo outputs from four different
Sources / channels as inputs and a single chosen by them is / are connected
Exit at any time.

When power is turned "on" Channel A (A1 and A2) is selected. If not,
The audio is on Channel A, the circuit waiting for some time and then
the next channel (channel B), The The search operation continues until it is detected
The audio signal on a channel. The other channels have to wait or delay
The time can be set by Preset VR1. If the time longer
necessary, you can replace C1 Capacitor with a higher value.

Suppose that is, Channel A-line is connected to a tape recorder and the channel B
a radio receiver. The first time A channel is selected, the audio
the tape recorder be present Edition. After the tape is played entirely
or if you have enough rest between successive shots, the circuit automatically launch
radio receiver. To manually from a jump (selection) active channel, press the jump
switch (S1) at the time, one or more times until the desired input channel
selected. The selected channel (A, B, C, or D) is indicated by a light
LED (LED 11, LED 12, LED13 and LED14, respectively).

Analog IC CD4066 contains four switch. These switches are four separate channels. For stereo operation, two similar chips CD4066 as shown in the circuit. These analog
The switches are controlled by IC CD4017 outputs. CD4017 is a 10-bit ring
IC against. Since only one of its outputs high all the time, only a
Switch is closed at a time. IC CD4017 is a ring of 4-bit configuration
Connecting the fifth counter output Q4 (pin 10) on the reset pin. Capacitor
C5, in conjunction with R6 forms a power-on reset circuit for IC2, so that
the first step "in the" power Supply, output Q0 (pin 3) is always 'Strong'. The watch is expected CD4017 IC1 (NE555), which acts as a astable multivibrator when transistor
T1 is in state court.

IC5 (KA2281) is not used here just to point out that the audio level
selected channel stereo, but also transfer Polarization of the transistor T1. Only
a certain threshold of audio detected in a selected channel, the pin 7 and /
or pin 10 of IC5 goes "low." This low Level is the base of the transistor, along
T1 with diode-resistor combination of D2-R1/D3-R22. As a result, the transistor
T1 conducts and the cause of the output IC1 to remain "low" (off), if
selected channel's output exceeds audio threshold setting.

Preset VR2 VR3 were recorded and Set individual audio- The thresholds of the left stereo channels, if desired. Once the multivibrator Effect of IC1 is disabled, the output of IC2 does not change. Therefore, research through the channels until receives an audio signal and "higher preset threshold. The jump S1 is also used to move a channel when the selected sound in the channel. The number of channels can extended to ten, the use of new 4.066 chips.

Audio Isolation Amplifier

• R1, R11 56 kOhm   C1, C11 470 nF 
• R2, R12 39 kOhm C2, C12 2,2 uF (mikrofarad) 
• R3, R13 180 kOhm C3, C13 4,7 uF (mikrofarad) 
• R4, R7, R14, R17 15 kOhm C4, C14 15 pF, Ceramic
• R5, R9, R15, R19 10 Ohm C21, C22, C25, C31, C32, C35 100 nF, Ceramic
• R6, R16 120 kOhm C23, C33 1000 uF (mikrofarad) / min. 16 V 
• R8, R18 470 Ohm C24, C34 100 uF (mikrofarad) / min. 10 V 
• R10, R20 100 kOhm C26 10 nF/630 V= (275 V~)
• R21, R31 390 Ohm T1, T3, T11, T13 BC559C (BC177, BC308, BC558 ...) 
• R22, R32 1,8 kOhm T2, T4, T12, T14 BC549C (KC238, BC238, BC548 ...) 
• R23 4,7 kOhm U21, U31 B250C1000DIL, diode stek DIL / DIL bridge 
• P1 10 kOhm / N, potenciometr D21, D22, D31, D32 1N4148, KA262 apod./or eq. 
• IO21, IO31 LM317L 
• Transformor 0,5 W
• 230 V / 2x 9 V LED LED 2 mA 

PCB

40 LED for Bikecycle

Light flashes alternately the rhythm of the IC

PCB : 1

PCB : 2