PULSEd CCS LED circuit

Status
Not open for further replies.
O

onoffman

Member level 3
Joined
Feb 9, 2010
Messages
56
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,286
Visit site
Activity points
1,727
Made CCS LEd circuit and worked well .

did trial with 158ma with two SMD 5050LED (>120mA rated ) They seem to light nicely

same LEDs i have an array of LED

as in the second pic , technically they need 240mA rated current , I want to overload with the plused circuit .


i have seen the led at the pulse circuit blink and when connected to the CCS circuit
it goes to higher frequency very fast blink .

Will it give long life ?
How do i know my pulsed circuit is going good narrow pulses .
 

Attachments

  • ccs-pullsed.png
    61.1 KB · Views: 82
  • led-aa.png
    10.2 KB · Views: 70

Dont use leds parallel, (you may search it why),
square wave generator you used is an ancient way
and mainly used for illustrative purposes only,
at least you may use ne555 for generating square wave.
Also the current limiting system is wasting energy on 3.9 ohm,
but for 150-200mA it is not a big deal,
maybe you may use LM317 regulator as a current limiter.
In fact, you dont need pulse generator,
you may only use ccs,
pulsed leds tires the eyes faster.
 

NEVER connect LEDs in parallel unless you match their forward voltage.

Pulsed LEDs appear to be dimmed which is why Pulse-Width Modulation is used to dim car and bus tail lights. Your eyesight needs an on-time of 30ms or longer to have the same brightness as continuous current.
If you pulse with over-current at a low frequency then the long on-time allows the LEDs to overheat and fail soon.
 
Last edited:

Status
Not open for further replies.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…