yclo
Flashaholic*
Is it possible to build a circuit to simulate the Arc torches regulated output? Just so that the light doesn't dim as the battery dies down. Or is that classified information?
Top secret?
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Steelwolf
Flashlight Enthusiast
There is an item in the **** Smith's catalog (K3019) which is a 6 LED flashlight running on 1 D cell and the description claims that it gives "constant brightness over cell life". That might be a regulated circuit such as you described?
I'm waiting till they stock it in one of the Perth stores, but I will definitely get it when it comes in.
So far, though, I have not yet been able to build a regulated circuit. Certainly, I've done boosters, but they aren't regulated like that. You could, of course, just go with the commercially available ICs such as the National Semiconductor LM2621 (cr?). These are regulated boosters. There are regulated bucks as well. But there has to be a simpler solution. You can't fit a lot of electronics in the head of an Arc-AAA, so I'm sure the circuit is quite simple.
I'm waiting till they stock it in one of the Perth stores, but I will definitely get it when it comes in.
So far, though, I have not yet been able to build a regulated circuit. Certainly, I've done boosters, but they aren't regulated like that. You could, of course, just go with the commercially available ICs such as the National Semiconductor LM2621 (cr?). These are regulated boosters. There are regulated bucks as well. But there has to be a simpler solution. You can't fit a lot of electronics in the head of an Arc-AAA, so I'm sure the circuit is quite simple.
I had never heard of **** Smith...
Any idea where you could get one of these in the USA?
Kit 6-LED Torch SC 5/01
Generates super soft white light and constant brightness. Ideal for night walking, emergency vehicle maintenance and camping. uses 6 LED's and runs from a single D cell battery for extra long life.
New!
Cat No. K3019 A$52.80
Add to Basket
Any idea where you could get one of these in the USA?
Kit 6-LED Torch SC 5/01
Generates super soft white light and constant brightness. Ideal for night walking, emergency vehicle maintenance and camping. uses 6 LED's and runs from a single D cell battery for extra long life.
New!
Cat No. K3019 A$52.80
Add to Basket
Steelwolf
Flashlight Enthusiast
KenBar: **** Smith is an Australian entrepenuer (sp?). He set up this retail chain for electronics goods (computers, tv, radios, transceivers, gadgets, etc.) His store is one of the main sources for parts for electronics hobbyists.
I think the closest equivalent in USA is Radioshack, but while ****ie brings in stuff from them, I don't know if they import any of ****ie's stuff. Still, I suppose you could check them out.
If you really would like one to play with, when they become available at my local DS store, I could get one to send to you. Or you can order straight from the website.
In the mean time, are there any good and simple regulating circuits out there?
I think the closest equivalent in USA is Radioshack, but while ****ie brings in stuff from them, I don't know if they import any of ****ie's stuff. Still, I suppose you could check them out.
If you really would like one to play with, when they become available at my local DS store, I could get one to send to you. Or you can order straight from the website.
In the mean time, are there any good and simple regulating circuits out there?
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by John N:
http://www.cs.indiana.edu/hyplan/willie/lvr.html<HR></BLOCKQUOTE>
Oops. Should have checked the FAQ first:
Can I run LED's, strobe lights or other electronics off the LVR?
No, the LVR does not put out DC. It puts out Pulse Width Modulation of the battery voltage. It is only suitable for filament light bulbs. LED's can be hooked up with a series resistor, but this isn't
an efficient way to do this.
LED's can be run on a constant voltage DC source but really they need constant current. There are many DC to DC current mode convertors that can be used for LED's. The problem with white
LED's: are far less efficient (when driven hard IE > 50mA) at producing light than a good halogen incandescent light bulb at the lumen levels that most climbers, cavers, and cyclist need. If you
only need 1 to 5 lumens LED's are nice, but if you want 40 to 100 lumens they are very expensive way to produce less light and light of poor color temperature with more power consumption
than a halogen light bulb. However, for low light needs they can work great and if you build large array and keep the per LED current low (< 20mA) you can achieve higher efficiency than light
bulb.
Strobe lights have a DC to DC convertor in them and so need DC as an input. Many other electronics like radios, tape players etc. also need a DC input.
http://www.cs.indiana.edu/hyplan/willie/lvr.html<HR></BLOCKQUOTE>
Oops. Should have checked the FAQ first:
Can I run LED's, strobe lights or other electronics off the LVR?
No, the LVR does not put out DC. It puts out Pulse Width Modulation of the battery voltage. It is only suitable for filament light bulbs. LED's can be hooked up with a series resistor, but this isn't
an efficient way to do this.
LED's can be run on a constant voltage DC source but really they need constant current. There are many DC to DC current mode convertors that can be used for LED's. The problem with white
LED's: are far less efficient (when driven hard IE > 50mA) at producing light than a good halogen incandescent light bulb at the lumen levels that most climbers, cavers, and cyclist need. If you
only need 1 to 5 lumens LED's are nice, but if you want 40 to 100 lumens they are very expensive way to produce less light and light of poor color temperature with more power consumption
than a halogen light bulb. However, for low light needs they can work great and if you build large array and keep the per LED current low (< 20mA) you can achieve higher efficiency than light
bulb.
Strobe lights have a DC to DC convertor in them and so need DC as an input. Many other electronics like radios, tape players etc. also need a DC input.
Steelwolf
Flashlight Enthusiast
With this LVR thing, you could use it in an LED setup. You would need to add a smoothing capacitor in parallel with the LEDs to take up the portion of the job that the filament in a bulb would do naturally, but it could work.
PeLu
Flashlight Enthusiast
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Steelwolf:
With this LVR thing, you could use it in an LED setup. You would need to add a smoothing capacitor in <HR></BLOCKQUOTE>
No, absolutely not. The Willie Hunt LVR is ONLY aimed at incandescent bulbs and will not bring any senceful results with other light sources. Just forget about it.
With this LVR thing, you could use it in an LED setup. You would need to add a smoothing capacitor in <HR></BLOCKQUOTE>
No, absolutely not. The Willie Hunt LVR is ONLY aimed at incandescent bulbs and will not bring any senceful results with other light sources. Just forget about it.
Steelwolf
Flashlight Enthusiast
PeLu, This might be asking a little too much of you, but is it possible to explain why it doesn't work?
PeLu
Flashlight Enthusiast
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Steelwolf:
PeLu, This might be asking a little too much of you, but is it possible to explain why it doesn't work?<HR></BLOCKQUOTE>
The Willie Hunt LVR puts constant power into resistive loads. At the frequency it is working, incadescent bulbs are resistive loads (even if some people invent physics new and explain it different).
LEDs are by far no resistive loads, they are behaving different.
Willie's website explains it (quoted by John N), why don't you believe it?
PeLu, This might be asking a little too much of you, but is it possible to explain why it doesn't work?<HR></BLOCKQUOTE>
The Willie Hunt LVR puts constant power into resistive loads. At the frequency it is working, incadescent bulbs are resistive loads (even if some people invent physics new and explain it different).
LEDs are by far no resistive loads, they are behaving different.
Willie's website explains it (quoted by John N), why don't you believe it?
Steelwolf
Flashlight Enthusiast
PeLu, Sorry if I come across as not believing. The truth is I don't understand what he explain. You seem to be getting a little annoyed with answering my questions, so I will stop now. Thanks for your patience so far.
