A simple but useful circuit to solve
the problems with parking car, in spaces without good visibility. The
electric circuit appears in picture 1. It is constituted by the IC1 and
components round he. When the car bumper touch soft and push lightly
the switch S1 then of battery voltage + 9 V it is applied in the
circuit, the transistor Q1 turn ON and the diodes D3-4 they blink. After
4 seconds the capacitor C1 charging. The pin 9 of IC1c it goes in high
potential, simultaneously the pin 10 goes in low potential and Q1 turn
off and the diodes turn off and the circuit it remains in situation of
waiting, until the next excitation of switch S1.
The consumption in the this stage remains
very small, without it aggravates the battery. The use in the place of
D1, Flash Led is not indispensable. Led it can replaced with one
simple led 5mm, the lighting then will remain continuous for 4 seconds
and then it will close. We can change the time that remains turned on
the Led changing the capacity C1. With C1=10uF the time goes up in the
10 seconds.A opinion of placement of switch S1 appears in picture 2.
The circuit, the switch S1 and the battery, are placed in a box, which
is not influenced easy by the humidity. The two Led can with a cable be
placed somewhere highest, so that they are visible from the driver
seat. The place of S1 can be varied with types of switches such as
push ON with plate. Suitable adaptation and extension of plate it can
become as long as need. In the end of plate put a small piece of
elastic, in order that when car bumper touch on it, it does not destroy
the colour.
Parts List
IC1=4093 R1 = 10Kohms 1/4W C2 = 100nF 100V MKT
Q1=BC550 R2=1Mohms 1/4W J1=2pin Connector
D1=1N4148 R3 = 4.7Kohms1/4W S1=sw normal open
D2=Led 5mm Red normal or Flash R4 = 820ohms 1/4W 9V battery with clip
D3=Led 5mm Red normal C1=4.7uF 25V [for ~4sec delay time]
