Small light bar ( work in progress)

[g7mjv]

l'm a member of an emergency comms team and occasionally it's helpful to have some strobing amber lights.

l've started this project using 3 watt amber prolights mounted on a 3 sided 1.5" ali extrusion.

[BVnursery]

Gotta suggest either some tape or a grommet for the area where the wires go inside your setup.

[g7mjv]

l've modified it a little. l've applied some epoxy resin (araldite) on a couple of points around the LEDs and removed the bolts. The thermal compound is in place and so far so good.

The origional holes were well deburred so l've added some heat-shrink to the cables and slotted them through the bolt holes.

[justDIY]

looks a lot cleaner!

what are you using for the strobe effect, a simple 555 circuit, or something fancier?

[g7mjv]

My intention is to fit more prolights, probably a total of 6.
l have a circuit that switches some smaller leds but the switching transistors are only supposed to be good for 700ma so l need to look further...

My circuit uses copper strip board with horizontal strips



Laid out like this...



Now, the 2n2222 will only handle 700ma ( l think) so l need to find something far beefier to handle 5 or 6 prolights on each of the 2 channels, Any suggestions would be greatly appreciated

[justDIY]

why are you using opti-isolators, and what does "mobo header" mean?

grab some TIP101 transistors; they're cheap as dirt from surplus huts, you'll want a mica shim or some other sort of insulation to stop it from shorting out if you mount it to your big heatsink... or just get it it's own little heatsink.

http://www.bgmicro.com/index.asp?PageAction=VIEWPROD&ProdID=10446

another good one to watch out for is the IRF510 or IRF520 mosfet, they're a cold war era transistor that can switch decent loads, without a heatsink

that 4060 chip you're using is a hard to find item... you might want to consider the 555 for future projects, or look at learning Picaxe - then you can program one chip to generate several different flash patterns

[g7mjv]

Hi

The cct with the opto was one suggested for people wanting to run more than l hard drive led on a pc. l adopted it and connected it to the 4060.

l shall look into some 555 info and see if l can build something fit for purpose. l've never played with pics but l suppose it's never too late to learn..

Many thanks for the transistor info

[edit] Got hold of some IRFZ44Rs yesterday

[cadstarsucks]

Hi

The cct with the opto was one suggested for people wanting to run more than l hard drive led on a pc. l adopted it and connected it to the 4060.

l shall look into some 555 info and see if l can build something fit for purpose. l've never played with pics but l suppose it's never too late to learn..

Many thanks for the transistor info

[edit] Got hold of some IRFZ44Rs yesterday

Actually it is the entire 4000 series that is hard to find.  The 74HC4060 is not that hard to find and there is really not reason to run the circuit at 12V anyway when a simple regulator would take care of that and be much less static sensitive (the 4000 series is notoriously static sensitive and tend to blow when you look at them cross eyed)

Dan

[g7mjv]

Thanks for the info, much appreciated

The 4000 series seem easily available over here but alternative suggestions would be welcome..

[justDIY]

Thanks for the info, much appreciated

The 4000 series seem easily available over here but alternative suggestions would be welcome..

the LM555, NE555, TI555, K555, etc, is the modern day timer chip used in all sorts of 'blinker' applications.

Dan's recommendation of the 744060 will work too, although it's not as easy to find as the 555

i haven't met an led blinking application yet that couldn't be handled with a microcontroller - you might want to look at the PICAXE chips - they're not very powerful in terms of memory or features, but they are super easy to program (with free software) and require no special programmer, just a plain serial cable and some resistors.  One of the small ones would certainly be able to do lots more than simple logic chips in terms of flashing and sequencing leds.

[g7mjv]

Hi

l've certainly heard of pics but l've never really been sure where to start.. l will do some research when l get time and see what l can come up with..

Many thanks