Input Needed for Next Project Idea

So I love my 2 Senkat GB burners, they're tons of fun. But I want something as cool as they are that I can use more often, such as in presentations. A Bluray is, of course, perfect for this! BUT, I do love the burning capabilities of those awesome reds, and I don't want to have to carry 2 lasers. Whatever is a man to do? How about putting them BOTH in one flashlight unit! That's it! And since it'll need to be fairly large anyway, what about incorporating some active cooling for a nice phazor or open-can diode so it can burn even better than the GB diodes I have, and I can even use the red built into the Bluray case to throw people off of its true identity, So, this is what I have so far:



Some of my thoughts on features, contents, and concerns:

1. Finding the right 2 pole-3 contact selector switch is proving difficult. I found a switch that does the right connections here http://info.tactnet.co.jp/copal/e/product/pdf/switches/ss10&s2050_en.pdf, but it's only rated to 100 mA, and I can't find one to handle the current that I'd like to feed the phasor (a 500 mA rating would suffice, me thinks). Ideally, this rotary selector switch will allow only one diode on at a time, and would be sunk into the housing so as to not allow switching without deliberate effort and a tool of sorts, such as a screwdriver I could keep on my keychain.

2. I haven't found a momentary switch that's perfect yet, for the 500 mA rating and the simultaneous parallel lines that are not allowed to touch, but I think this should be doable. If nothing else, I could use 2, but one would be better (for camouflage).

3. It WILL have a safety switch that only I can manipulate for the high-power red diode, separate from the selector switch. For this, I like the idea of a post I read on here about magnetic reed switches, which will be on when a magnet is placed in a certain location on the housing.

4. A similar reed switch, if it proves feasible, would be great for the toggle on/off for the peltier active cooling for the high-power red. Otherwise, a regular toggle will suffice.

5. The batteries will, clearly, run down unevenly. The top battery will use very little current with just the Bluray while the bottom two have occasional high-power red duty. The bottom battery will also run the peltier, draining it further. I'm thinking of all this with these http://www.dealextreme.com/details.dx/sku.3273 in mind. Would there be any problems with the uneven use of the batteries? Would switching the order of the batteries often alleviate any possible problems and allow for even wear down? I'm just not a battery expert.

6. Also, I'm thinking that a complete device safety switch could be used between the negative terminal of the batteries and ground, would there be any need for this? The device will be left in weak red mode by default after usage, and the high-power red will have a safety of it's own, what do other mod-ers think of the usefulness or necessity of such a thing?

All in all, I'm after a pointer that I can use daily in presentations and such, just like a normal red, with an option for violet as well in presentations, that I can use as a burner when the occasion arises. However, I realize that this could expose the device, which I am extremely careful with, to others who may not know the full potential or danger of what they may be exposed to if they accidentally pick up my pointer. Therefore, I would like for such a device to be as fool-proof as possible, with no way for someone who doesn't know how to use it to activate the high-power red diode, and with deliberate action required to use the violet diode. Thoughts? Comments?

there must be some way to put a switch between the lm317 and resistor so that you can use just the 1?

If I did that, with 1 lm317 controlling the current for all three, I would end up having to run the max current I wanted for any of the 3, and bleed the rest of the current off elsewhere. So, if I want (just hypothetically) 416 mA for the high power red and only 38 mA for the bluray, that's 378 mA of current running out of the batteries that is being wasted any time the bluray is running. It would be a similar number for the red.

Also, the extra energy to supply the voltage that the bluray needs would be wasted as heat by putting it through the lm317 when running the reds. I also don't want to have an adjustable potentiometer for metering, I want it to be right on when I turn it on, all the time, with any of the 3 diodes. I know it will be a little big, I'm trying to figure out just how big now also.

Although you did give me an idea about a better way to handle multiple voltage requirements with one set of batteries a little better without wasting energy. Thanks for your help. **Off into thinking mode again**.

lm317 is going to be lowering the amperage for whatever diode is on. if you have the lm317 that goes to a switch before it goes to the resistor/laser you can select with the switch what resistor/laser you want to have on. im editing your picture to try to give a better idea what im talking about.

I think I got what you're saying, how about something like this. The extra voltage is still being put into the 317 when running the reds, but the current will match the appropriate sense diode with the 317. One no-no of this, however, is the capacitor being shared between the diodes. I know each diode needs its own capacitor soldered to it so that they can't disconnect and then reconnect, it's just easier to draw it this way for now. I'll fit that in the next iteration.

JECS said:

lm317 is going to be lowering the amperage for whatever diode is on. if you have the lm317 that goes to a switch before it goes to the resistor/laser you can select with the switch what resistor/laser you want to have on. im editing your picture to try to give a better idea what im talking about.

Click to expand...

That's true as long as you are not running more than one diode at a time. I would use a 317 for the peltier, a 317 for the laser diodes, and a low drop out regulator for the blu-ray. That way you could run everything off of 2 RCR123's, and draw the current evenly from the batteries.

yeah that looks better. lm317 may not be that big but that'll save some space and save some money on components

yeah im wondering about the capacitor. i dont know much about electronic theory. i just find existing circuits and build them usually.

Remember the regulator is going to put out more than 5 volts with no load across the output. So when you switch to a different diode it will get the full 5 plus volts. I am not well enough versed in electronics to know if the capacitor would absorb the spike in this configuration, assuming the capacitor is soldered directly to the diode.

Gazoo said:

[quote author=JECS link=1201748695/0#3 date=1201752196]lm317 is going to be lowering the amperage for whatever diode is on. if you have the lm317 that goes to a switch before it goes to the resistor/laser you can select with the switch what resistor/laser you want to have on. im editing your picture to try to give a better idea what im talking about.

Click to expand...

That's true as long as you are not running more than one diode at a time. I would use a 317 for the peltier, a 317 for the laser diodes, and a low drop out regulator for the blu-ray. That way you could run everything off of 2 RCR123's, and draw the current evenly from the batteries.[/quote]


So you'd think of something like this? The one thing I don't like about this is having to have 2 rotary/selection type switches. It would be better to have only 2 batteries, and to draw them all evenly, just like you say. Decisions, decisions.

I think that's better but the AMC7135 will not power a blu-ray and can not run on more than 4.5 volts. If you can find a 5 volt low drop out regulator, you could get away with using it. All you need to do is put a pot in series with the diode. Something like this but there are others on e-bay. Search for LDO regulator

http://cgi.ebay.com/MIC5201-5-0BS-V...eZWD1VQQtrksidZp1638.m118.l1247QQcmdZViewItem

I would be very careful switching at output of the LM317. The output can swing high (unloaded) during the switching process and the LDs will likely receive voltage spikes.

Don't forget about relays, they are your friend when you want to use small switches with higher currents, plus with all the available types, they can sometimes solve other problems.