Building a simulated flame lamp, few questions on the wiring!

[djwirk]

Okay, so I've taken apart and put back together my fair share of electronics, and I'm comfortable enough with wiring/soldering etc. so I'm sure this is doable, but without schematics, my limited electrical knowledge might not be quite enough to get the circuit running (Safely!).

I'm planning on wiring three MR16 halogen lamps w/some homemade gel filters in a circuit w/a computer case fan (Voltage: 12 Volts, Voltage Range: 6.5 ~13.8 Volts, Input Current: 0.30 Amp Max)

First question, will the following transformer work w/the halogen (Not LED) bulbs and the fan as well? If not, what specifications do I need?

MR16 12V LED DRIVER SWITICHING POWER SUPPLY TRANSFORMER
Input Voltage
AC 85-265 Volt
50Hz/60Hz
Output Voltage
DC 12V/650mA
(max 8w)

If so, do I wire them all in a continuous circuit or wire each direct from the transformer?

If this all works, I'd like to put some kind of a dimmer in the circuit, I've read that a pot or rheostat on the 12v end is not the way to go due to a waste of power?

Basicly, I'm confident I can put it all together, if anyone can give me some tips on wiring it all and letting me know if this is doable! thanks!

 

[KJ6EAD]

Your power supply is too weak to supply enough current for all that. MR16 size halogen bulbs use between 5W and 75W each so there's at least 15W used right there. Add another 3.6W for the fan and you're up to 18.6W, more than twice the 8W that the supply can provide.

If you had 20W MR16 halogen lamps, a somewhat typical value, you'd need a 6A power supply.

 

[djwirk]

Thanks! For the circuit I'm planning, where's the best place to get a transformer? Ebay? Radio Shack? I'm looking to get one I can tuck inside the unit since the fan will vent the heat anyway, not a wall adapter.

 

[KJ6EAD]

The power supply you have can be used for the fan. Are you looking to run the lamps from AC or DC; and what are the wattages?

 

[djwirk]

Really not sure, whatever's standard I suppose? I'd like to just be able to pick up bulbs at WM and have it be capable of taking whatever.
Thanks again, will use the PS for the fan and figure something else out for the lamps!

p.s. What about regulating the voltage to the fan/lights on the 12v end? What are my options to dim the bulbs, or slow the fan? Don't mind waiting for shipping if I can get something cheap from asia, if the whole project works, I don't mind stepping up the build quality, but want to go cheap until I verify it looks decent!

p.s. - will this PS work for the lamps? Not really sure since it's stated 110V input, is that a problem in the US, or close enough? I know line voltage sags/etc. during the day, and they should be functionally interchangeable, but just want to double-check before I buy a transformer.
**broken link removed**

 

[djwirk]

Reading up more, for power efficiency is my best bet for the light dimmer a 12v 60w pwm? See some pretty cheap on eBay.

 

[KJ6EAD]

I was under the impression that you already owned the lamps. If not, why not use LEDs? They're safer, cooler, last longer and require far less power. Halogen lamps are really nothing but heaters that make a little light (≈5% efficient for lighting).

PWM is the preferred method for dimming, but this is the first you've mentioned the need for anything more than an ON/OFF arrangement. Do you have any other design requirements you haven't mentioned?

If you're looking for a fire simulation, try searching for Halloween, DJ and theatrical special effects lighting devices. There are plenty available, already designed and tested, ready for sale.

 

[djsfantasi]

...and there are circuits published that will do the job as well, such as this one Interesting Electronic Schematics and Circuits - Novotill

 

[djwirk]

I was under the impression that you already owned the lamps. If not, why not use LEDs? They're safer, cooler, last longer and require far less power. Halogen lamps are really nothing but heaters that make a little light (≈5% efficient for lighting).

PWM is the preferred method for dimming, but this is the first you've mentioned the need for anything more than an ON/OFF arrangement. Do you have any other design requirements you haven't mentioned?

If you're looking for a fire simulation, try searching for Halloween, DJ and theatrical special effects lighting devices. There are plenty available, already designed and tested, ready for sale.

I'm okay with using LED.
Will that ps be enough for the fan and three lamps?

Would like to be able to adjust the brightness if possible.

I know I could just buy a lamp, but I'm a hobbyist and this is something I'd like to get into! Having fun with it!

 

[KJ6EAD]

There's enough power for some LEDs and the fan depending on how many and what kind of LEDs. You could set up some red and yellow LEDs with your fan and streamers. Dimming can be done by various methods depending on how you're supplying current to the LEDs. I always recommend using an LM317 voltage regulator in the current regulating configuration.

There are lots of ways to simulate flame and candle flicker effects with LEDs and no fan or gels would be required. The circuits that do this inherently vary brightness of the LEDs. The circuit given by djsfantasi above is a good one since it doesn't require a microcontroller.