Soft Start Lighting
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SteveSmith
- Posts: 13
- Joined: Wed Jul 06, 2005 7:18 pm
Soft Start Lighting
Has anybody out there come across a simple circuit that will cause an LED to slowly light up? I would like to have a model engine "power up" over the course of several seconts. Any ideas would be greatly appreciated!
He disappointeth the devices of the crafty, so that their hands cannot perform their Enterprise.
--Job 5:12 KJV
--Job 5:12 KJV
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Sparky
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Yes an analog circuit was made that has something close to this effect. . .it's from a UK site on computer fan controllers:
http://www.cpemma.co.uk/throbber.html
<A HREF="http://www.kc6sye.com/techmages_3_17_04_c.html" target="blank">here's some clips of the circuit</A>
If you've seen the clips of the J-57 space astation from Wonderfest 2004 the shuttle bay entrance lights are on a circuit from the above desing, two more circuits where built to power the four leds in the station neck joint in pairs. One throbbing at a fast rate the other at a slower rate to look like different power systems running on different loads.
http://www.cpemma.co.uk/throbber.html
<A HREF="http://www.kc6sye.com/techmages_3_17_04_c.html" target="blank">here's some clips of the circuit</A>
If you've seen the clips of the J-57 space astation from Wonderfest 2004 the shuttle bay entrance lights are on a circuit from the above desing, two more circuits where built to power the four leds in the station neck joint in pairs. One throbbing at a fast rate the other at a slower rate to look like different power systems running on different loads.
<a href="http://www.kc6sye.com/2_wheresaneatpart.jpg" target="_Sparky">Is this plastic thingy on the counter a neat part?</a> <a href="http://www.kc6sye.com/1_casting_inprogress.jpg" target="_Sparky">Let's cast it.</a>
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en'til Zog
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- Location: The Wilds of Northwoods Wisconsin
One simple 'brute force' method that I've used just involves a normal ON/OFF LED controller (like a CMOS 4023), a plain signal control diode (NOT ad LED) in series with the LED - which is paralleled with a HUGE capacity capacitor - 600 uF is a start. The cap goes around the LED.
When the circuit says "ON" the cap slowly charges, sucking up most of the available voltage at first, then as it 'fills' letting more and more flow into the LED which brightens slowly. When the control says "OFF" the cap slowly discharges through the LED letting it fade. The signal diode keeps the cap from discharging back through the control circuit.
In ove version of this simple circuit mod I've gotten a slow on / slow off cycle of about a minute
S L O W.....
Sparky's circuit works very nicely too!
When the circuit says "ON" the cap slowly charges, sucking up most of the available voltage at first, then as it 'fills' letting more and more flow into the LED which brightens slowly. When the control says "OFF" the cap slowly discharges through the LED letting it fade. The signal diode keeps the cap from discharging back through the control circuit.
In ove version of this simple circuit mod I've gotten a slow on / slow off cycle of about a minute
S L O W.....
Sparky's circuit works very nicely too!