Flashing 5watt led?

[(*steve*)]

Good job Chris!

I can understand your desire for missile pods.

You may find that a bright orange flag sticking out on a stick on your left hand side works a treat. Not so much because card don't want to hit you, but because they don't want to get their paint scratched!

 

[samsm255]

Ok this thing is going cost me bit to much money to do with the high power LED. Would it be less if it wasn't a high power led and maybe just something like this? http://www.digikey.com/product-detail/en/R42180/897-1023-2-ND/2182264 Talking to a guy that sells the parts I'll need for this in my town said something about q1/r4 10 area In the schematic you drew is going cost alot of money for the part Idk what it is some type of switch. Also the heat sink thing would Cost me bit too.
Good news...I also talked to them on that web site you told me get the LED from (Digi-key) and they told me they will take the lights back in a return. That good web site you gave me they helped me out alot with the chats and stuff about questions about cost and ect

 

[CDRIVE]

No, at 350mA you'll still need a driver transistor. Besides, this LED is only 50mA less than your last pick.

Anyone see any reason that he couldn't use a cheap 2N2222? Check my last schematic that I posted. His duty cycle will be 50mS or less and the freq is only 1.6Hz.

Chris

 

[samsm255]

Guess I'll need point that out to him tomorrow because looked around google and it should cost like $2-1? I also have three questions of my own.
1: Does this thing really use 3 capacitors?
2: Does this thing really need a heat sink/thing?
3: Where would the ends of the 2N2222 go?

 

[CDRIVE]

Anyone see any reason that he couldn't use a cheap 2N2222? Check my last schematic that I posted. His duty cycle will be 50mS or less and the freq is only 1.6Hz.

Chris

Yeah, I do! I think it could handle the brief load but Vce(Sat) would be too high.

Chris

 

[CDRIVE]

Guess I'll need point that out to him tomorrow because looked around google and it should cost like $2-1? I also have three questions of my own.
1: Does this thing really use 3 capacitors?
2: Does this thing really need a heat sink/thing?
3: Where would the ends of the 2N2222 go?

I've been wondering why I'm virtually alone in this topic. Are you guys enjoying this dialog? I think I'm approaching thermal runaway!

Chris

 

[samsm255]

I've been wondering why I'm virtually alone in this topic. Are you guys enjoying this dialog? I think I'm approaching thermal runaway!

Chris

Well im very new at this stuff and don't understand things that much, sorry

 

[CDRIVE]

Well im very new at this stuff and don't understand things that much, sorry

OK, listen up, so I don't have to repeat this information. You said that this is getting expensive but you weren't specific about what. The Q1 MOSFET is less than a dollar at Digikey. You need this FET (Field Effect Transistor) because these LEDs exceed the current limitations of the 555. The 555 turns Q1 on and off. Q1, in turn, turns LED1 & 2 on and off. You can think of it a relay of sorts.

There are only 2 capacitors on my schematic C1 is the timing cap while C2 is a small disk cap .01uF. It's used because the 555 manufactures recommend it when the pin 5 isn't being used. I also included it because my spice software that created my schematic doesn't like unterminated pins. This cap costs a few cents!

I will post an updated schematic that will include naming the Drain, Gate, Source pins of Q1. I will also include a basing diagram (pictorial) of Q1 so you will know which pins are are the Drain, Gate and Source.

R5 is a 5 Ohm - 2 Watt resistor. It's used to limit the LEDs current to 400 milliamps. The LR W5AM-HZJZ-1-Z LED can handle currents up to 1 Amp (Pulsed) at the expense of more heat and more than twice the battery drain. I will include R5 value for 800mA operation but I will probably shorten the pulse width too, as Steve suggested.

Heat sinking the LEDs is not an expensive proposition. It's just a matter of transferring the LEDs heat to metallic (usually aluminum) material. The manufacturers data sheet usually includes heat sinking info.

http://media.digikey.com/pdf/Data Sheets/Osram PDFs/LA_LR_LY W5AM.pdf

I'm sure that Digikey sells them too. Ask them, they should be cheap.

Chris

EDIT: I'm including the data sheet link for Q1. It includes the pinout.
http://www.vishay.com/doc?91307

 

[CDRIVE]

I was reading through the LED data sheet and it would appear that heat sinking is facilitated by a solder pad that is connected to the Anode of the LED. This is a surface mount LED as I believe all the high power models are. I've never worked with one because I've never had any need to. Flowing solder to the heat sink area at the center of the LED isn't going to be a trivial process for a novice. Perhaps some of our senior members, that have worked with them, can give you tips.

Chris

 

[BobK]

My tip would be to buy one on a star. These can then be bolted to a heat sink.

Bob

 

[CDRIVE]

My tip would be to buy one on a star. These can then be bolted to a heat sink.

Bob

Hi Bob and thanks for your input. I think you're describing the kind of LED that one of our member's (JPU) used in his equine dental headset. I must confess that I've not kept current on many of the available LEDs. Got a link or part number?

Thanks,
Chris

 

[CDRIVE]

It took me a bit of time digging through old posts. I think Bob is talking about something like this.

http://www.ledsupply.com/creexpg-w139.php

Chris

 

[samsm255]

No, at 350mA you'll still need a driver transistor. Besides, this LED is only 50mA less than your last pick.

Anyone see any reason that he couldn't use a cheap 2N2222? Check my last schematic that I posted. His duty cycle will be 50mS or less and the freq is only 1.6Hz.

Chris

schmetic call for a mosfet. the 2n2222 is not a mosfet

 

[BobK]

It took me a bit of time digging through old posts. I think Bob is talking about something like this.

http://www.ledsupply.com/creexpg-w139.php

Chris

Yep, the are already solderd to an aluminum "star" which provides some heat-sinking, and slots so that they can be bolted to a more massive heat-sink.

Bob

 

[CDRIVE]

schmetic call for a mosfet. the 2n2222 is not a mosfet

Uh..... that would be relevant if I hadn't designed the circuit.

Chris

 

[samsm255]

Don't mind me, I'm just lost again I've got all the parts I need but this 2n2222 transistor. Can't find it any where in any of the stores around my town. Could you please direct me to the right one on that Digi-key web site or else where please? This should be my Last request/question for everything. I have all this stuff down now but this last part I need.

 

[CDRIVE]

Yep, the are already solderd to an aluminum "star" which provides some heat-sinking, and slots so that they can be bolted to a more massive heat-sink.

Bob

It sounds like a good alternative for him. Thanks for the tip.

Chris

 

[CDRIVE]

No, at 350mA you'll still need a driver transistor. Besides, this LED is only 50mA less than your last pick.

Anyone see any reason that he couldn't use a cheap 2N2222? Check my last schematic that I posted. His duty cycle will be 50mS or less and the freq is only 1.6Hz.

Chris

Yeah, I do! I think it could handle the brief load but Vce(Sat) would be too high.

Chris

Don't mind me, I'm just lost again I've got all the parts I need but this 2n2222 transistor. Can't find it any where in any of the stores around my town. Could you please direct me to the right one on that Digi-key web site or else where please? This should be my Last request/question for everything. I have all this stuff down now but this last part I need.

As you can see by these quotes I second guessed myself and dismissed replacing the MOSFET with a 2N2222 almost immediately. Did you buy the IRLD014PbF MOSFET? Also, I thought you canceled the LEDs order until we found one you could work with. I told you that the LED you chose was going to be very difficult to solder and not recommended for a nube.

Chris

 

[samsm255]

Looking around that web site I couldn't really find any more Led's in the 100+lumen range. If did find one the lenses for them were out of stock or had by 100+ of them. And seeing how much fun we had with this whole thing and misunderstandings ect may be better If we just go for this LED. Since we gotten so far with it. Unless you have another web site buy LEDs from other than that Digi-key site. And no I didn't get any transistors yet or what ever its called (2N2222 thing)

 

[(*steve*)]

If you type 2N2222 into digikeys search box, you'll find exactly the part that Chris suggests you DON'T USE. (you'll actually have 10 or so to choose from)

If you do the same with "IRLD014PbF", you'll find the right thing.

The only issue is that you should avoid parts that are surface mount (and Chris has been good enough to be very precise with the part numbering so you don't get offered any of those).