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LED or Lamp Pulser

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Circuits
Light Effects
LED or Lamp Pulser
LED or Lamp Pulser
Astonishing effect
4.5V supply
Circuit operation:
This circuit operates a LED in pulsing mode, i.e. the LED goes from off state, lights up gradually, then dims gradually, etc.
This operation mode is obtained by a triangular wave generator formed by two op-amps contained in a very cheap 8 pin DIL case IC. Q1 ensures current buffering, in order to obtain a better load drive.
R4 & C1 are the timing components: using the values shown in the parts list, the total period is about 4 seconds.
Notes:
* The most satisfying results are obtained adopting for R4 a value ranging from 220K to 4M7.
* Adopting for R4 a value below 220K, the pulsing effect will be indistinguishable from a normal blinking effect.
* The LED can be any type and color.
* You can use a filament lamp bulb instead of the LED, provided it is rated in the range 3.2 to 6V, 200mA max.
* Using a bulb as a load, R6 must be omitted.
* Voltage supply range can be 4 to 6V: 4.5V is the best compromise.
* Do not supply the circuit with voltages exceeding 6V: it will work less good and Q1 could be damaged when a bulb will be used as the load.
* At 6V supply, increase R6 value to 100 Ohm.
Source: http://www.redcircuits.com/Page51.htm
Copyright Flavio Dellepiane
4.5V supply
Circuit operation:
This circuit operates a LED in pulsing mode, i.e. the LED goes from off state, lights up gradually, then dims gradually, etc.
This operation mode is obtained by a triangular wave generator formed by two op-amps contained in a very cheap 8 pin DIL case IC. Q1 ensures current buffering, in order to obtain a better load drive.
R4 & C1 are the timing components: using the values shown in the parts list, the total period is about 4 seconds.
Notes:
* The most satisfying results are obtained adopting for R4 a value ranging from 220K to 4M7.
* Adopting for R4 a value below 220K, the pulsing effect will be indistinguishable from a normal blinking effect.
* The LED can be any type and color.
* You can use a filament lamp bulb instead of the LED, provided it is rated in the range 3.2 to 6V, 200mA max.
* Using a bulb as a load, R6 must be omitted.
* Voltage supply range can be 4 to 6V: 4.5V is the best compromise.
* Do not supply the circuit with voltages exceeding 6V: it will work less good and Q1 could be damaged when a bulb will be used as the load.
* At 6V supply, increase R6 value to 100 Ohm.
Source: http://www.redcircuits.com/Page51.htm
Copyright Flavio Dellepiane
Partlist
R1,R2___________4K7 1/4W Resistors
R3_____________22K 1/4W Resistor
R4______________2M2 1/4W Resistor (See Notes)
R5_____________10K 1/4W Resistor
R6_____________47R 1/4W Resistor (See Notes)
C1______________1µF 63V Polyester Capacitor
D1_____________5mm. Red LED (See Notes)
IC1__________LM358 Low Power Dual Op-amp
Q1___________BC337 45V 800mA NPN Transistor
R3_____________22K 1/4W Resistor
R4______________2M2 1/4W Resistor (See Notes)
R5_____________10K 1/4W Resistor
R6_____________47R 1/4W Resistor (See Notes)
C1______________1µF 63V Polyester Capacitor
D1_____________5mm. Red LED (See Notes)
IC1__________LM358 Low Power Dual Op-amp
Q1___________BC337 45V 800mA NPN Transistor
Files
Comments
May 30 2007 22:34
Rich Gress
are r1 and r2 47 K or 4.7K or what
is r4 really 22 meg or is it just 2 meg lol
what the heck is the value of r6
y does c1 have to be 63v
is r4 really 22 meg or is it just 2 meg lol
what the heck is the value of r6
y does c1 have to be 63v
Mar 24 2009 19:37
John Galpin
Would you please tell me what the "A" in the value of the capacitor is 1AuF. Also would you include the answer you gave to Mr. Rich Gress on the values of the resistors 4K7,2M2,47R
Mar 25 2009 8:41
Jospfh
That was an error in the page which is removed now, Thanks.
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