Showing posts with label lights. Show all posts
Showing posts with label lights. Show all posts
Monday, September 30, 2013
Magic Lights
The circuit as shown in the figure employs 14 bi-colour (red and green) LEDs having three terminals each. Different dancing colour patterns are produced using this circuit since each LED can produce three different colours. The middle terminal (pin 2) of the LEDs is the common cathode pin which is grounded. When a positive voltage is applied to pin 1, it emits red light. Similarly, when positive voltage is applied to pin 3. it emits green light. And when positive voltage is simultaneously applied to its pins 1 and 3, it emits amber light. The circuit can be used for decorative lights. IC1 (555) is used in astable mode to generate clock signal for IC2 and IC3 (CD4518) which are dual BCD counters.
Both counters of each of these ICs have been cascaded to obtain 8 outputs from each. The outputs from IC2 and IC3 are connected to IC4 through IC7 which are BCD to 7-segment latch/decodor/driver ICs. Thus we obtain a total of 14 segment outputs from each of the IC pairs consisting of IC4 plus IC5 and IC6 plus IC7. While outputs from former pair are connected to pin No. 1 of all the 14 bi-colour LEDs via current limiting resistors, the ouputs of the latter pair are similarly connected to pin No.3 of all the bi-colour LEDs to get a magical dancing lights effect.
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Both counters of each of these ICs have been cascaded to obtain 8 outputs from each. The outputs from IC2 and IC3 are connected to IC4 through IC7 which are BCD to 7-segment latch/decodor/driver ICs. Thus we obtain a total of 14 segment outputs from each of the IC pairs consisting of IC4 plus IC5 and IC6 plus IC7. While outputs from former pair are connected to pin No. 1 of all the 14 bi-colour LEDs via current limiting resistors, the ouputs of the latter pair are similarly connected to pin No.3 of all the bi-colour LEDs to get a magical dancing lights effect.
Tuesday, April 9, 2013
Sequential Turn Lights Driver Four LED left and right sequence Particularly suited to motorcycles
Parts:
R1_____________500K 1/2W Trimmer Cermet or Carbon
R2______________47K 1/4W Resistor
R3,R4____________1K 1/4W Resistors
R5,R6,R7,R8_____10K 1/4W Resistors
C1_______________1µF 63V Polyester or electrolytic capacitor
C2_____________220µF 25V Electrolytic capacitor
D1-D8__________LEDs Yellow ultra-bright types
Q1,Q2,Q3,Q4___BC337 45V 800mA NPN Transistors
IC1____________7555 or TS555CN or TLC555CP CMos Timer IC
IC2____________4017 Decade counter with 10 decoded outputs IC
SW1____________Vehicle Turn Lights switch (See Comments)
Battery_________12V Vehicle battery
Comments:
Thisdevice was designed on request and allows sequential operation of
four Leds either to left or right direction, obtained by means of a
7555 CMos timer IC (IC1) wired as an astable multivibrator driving a
Decade counter (IC2). This IC is set to count a sequence of four by
connection of pin #10 to pin #15, but any sequence count in the 2-10
range can be set by choosing the appropriate pin connection. Obviously,
LEDs, Transistors and their respective Base-limiting resistors must
also be added or omitted accordingly.
R1 is a variable resistor
(Trimmer), used to set the desired speed of the LEDs. SW1 is a
change-over switch that should already exist in your motorcycle,
having a center-off position and Turn-left and Turn-right positions.
D1, D3, D5 and D7 are the Turn-left LEDs; D2, D4, D6 and D8 are the Turn-right LEDs.
For a motorcycle they are arranged on a single board about 20 - 25 cm
wide as shown in the image below. The outer red LEDs are the
tail/brake lights and can be driven by a circuit like the LED driven
tail/brake Light Cluster available on this website.
Note:
- The use of high brightness, high efficiency yellow LED types of suitable size is mandatory.
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