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Post by kitbuilder on Jan 17, 2009 9:19:29 GMT -8
I have a circuit that flashes some LED's in sequence, what I want to do is increase the amount of light by using some incandescent lamps instead of the LED's.
So I need some sort of transistor switching that will handle about 12 volts at 400- 500 ma of current, but be driven by the typical 1-2 volt, 20 ma LED output that the flasher is outputting.
Any ideas??
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Post by Gary Lecomte on Jan 18, 2009 5:24:19 GMT -8
I have a circuit that flashes some LED's in sequence, what I want to do is increase the amount of light by using some incandescent lamps instead of the LED's. So I need some sort of transistor switching that will handle about 12 volts at 400- 500 ma of current, but be driven by the typical 1-2 volt, 20 ma LED output that the flasher is outputting. Any ideas?? Just a Transistor should do it. |
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Post by kitbuilder on Jan 19, 2009 5:54:12 GMT -8
Ok, Thanks Gary.
I didn't know if maybe some other associated components would be required.
Back to the breadboard.
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Post by Gary Lecomte on Jan 19, 2009 7:24:45 GMT -8
Ok, Thanks Gary. I didn't know if maybe some other associated components would be required. Back to the breadboard. Possibly a resistor or two, But I haven't seen your circuit to advise you better. |
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Post by kitbuilder on Jan 19, 2009 11:05:35 GMT -8
I wasn't trying to keep the circuit a secret, just trying to be brief. The circuit is a product of Velleman, their traffic light kit. The scheme can be found at this URL, www.vellemanusa.com/downloads/0/manual_mk131.pdfI want to use the basic timing cycle of this circuit, but I want to feed it to some larger lamps. Thus, the transistor switching scheme. I originally thought of a full size traffic light, which could be handled by a simple relays, but my wife didn't think it would look good in the living room. So it is now planned for the doorway to my workshop. Amazing how much peace was restored when I conceded where to put it, which did turn out to be a different place than where she told me to put it.  |
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rmeyn
Full Member
My primary interests are electronics, sailing, bowling, and camping
Posts: 163
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Post by rmeyn on Jan 20, 2009 8:22:27 GMT -8
Some thoughts. I looked at the circuit, but even with magnification I could not see it clearly. I would think, since it is a kit, that it would be hard to modifiy the existing circuit board. If you have the necessary expertise, I would work up a design and either breadboard it or use a simulator. Gary may have other ideas.
rmeyn
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Post by Gary Lecomte on Jan 20, 2009 16:30:00 GMT -8
I wasn't trying to keep the circuit a secret, just trying to be brief. The circuit is a product of Velleman, their traffic light kit. The scheme can be found at this URL, www.vellemanusa.com/downloads/0/manual_mk131.pdfI want to use the basic timing cycle of this circuit, but I want to feed it to some larger lamps. Thus, the transistor switching scheme. I originally thought of a full size traffic light, which could be handled by a simple relays, but my wife didn't think it would look good in the living room. So it is now planned for the doorway to my workshop. Amazing how much peace was restored when I conceded where to put it, which did turn out to be a different place than where she told me to put it. Sorry, I Can't do a Drawing for you, But its Quite Simple. The Existing Resistor (now to LED) Instead Goes to Base of a Transistor or Gate of a Mosfet. (What Transistor/Mosfet, Depends on the Current you require) Emitter (Source) goes to Ground. Your Light Bulb Goes between the Collector (or Drain) and Positive Supply. Should work OK, Gary. |
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Post by kitbuilder on Jan 21, 2009 4:33:01 GMT -8
Gary, thanks for your instructions. It is as I thought it would be, but as the old saying goes, "sometimes you can't see the forest for the trees". I wanted to make sure I wasn't missing anything. I have a supply of NPN transistors to choose from, so I will proceed.
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Post by kitbuilder on Jan 21, 2009 4:35:53 GMT -8
Richard,
No I wasn't planning to modify the existing PCB, just going to use the timing circuit. No sense in reinventing when the circuit is laying here. I will just jumper to another PCB that will carry the high voltage components.
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rmeyn
Full Member
My primary interests are electronics, sailing, bowling, and camping
Posts: 163
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Post by rmeyn on Jan 21, 2009 5:55:41 GMT -8
Richard,
No I wasn't planning to modify the existing PCB, just going to use the timing circuit. No sense in reinventing when the circuit is laying here. I will just jumper to another PCB that will carry the high voltage components. Sounds like a plan to me. I just couldn't see the plan clear enough. rmeyn |
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Post by Gary Lecomte on Jan 21, 2009 6:50:04 GMT -8
Richard,
No I wasn't planning to modify the existing PCB, just going to use the timing circuit. No sense in reinventing when the circuit is laying here. I will just jumper to another PCB that will carry the high voltage components. Sounds like a plan to me. I just couldn't see the plan clear enough. rmeyn I Downloaded the Latest version of Adobe reader (Ver.9) on this computer and it was almost useless. (33.6 Mb of CRAP) So I put that PDF on my older computer and using Adobe 6 running in a CD, I was able to select amd print Just the schematic portion, Clear as a Bell on 8.5 x 11, and Full Size of the page. Sometimes, Older is Better. |
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Post by kitbuilder on Jan 21, 2009 17:35:04 GMT -8
So I put that PDF on my older computer and using Adobe 6 running in a CD, I was able to select amd print Just the schematic portion, Clear as a Bell on 8.5 x 11, and Full Size of the page. Gary, Is that scheme in pdf form emailable? I would like a copy if it is. |
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Post by Gary Lecomte on Jan 23, 2009 7:04:33 GMT -8
No, I Can't Create a PDF.
But I could create a Picture File (JPG or PNG or GIF) of "Just the Schematic", and in a Reasonable Size.
Is that what you want?
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Post by kitbuilder on Jan 23, 2009 11:04:50 GMT -8
Thanks Gary, that would work for what I need.
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Post by Gary Lecomte on Jan 23, 2009 14:30:09 GMT -8
Thanks Gary, that would work for what I need.  How's this, A Photograph, Using my Camera. |
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