828 replies to this topic

[doktorstick]

On the "D" version, do the internal pot controls define the output current range from the dimmer control voltage range? For instance, as shipped, my 36-D at 10V on the dimmer circuit drives the LEDs at 1.5A. We made a simple circuit so our external pot only allows 6V to the dimmer circuit, which drives the LEDs at 1A.

What I'm wondering is if I need to crack my Meanwell open and calibrate the current range to max out at 1A for 10V of dimmer input.

Thanks.

Edited by doktorstick, 05 November 2009 - 08:57 AM.

[evilc66]

It's a good idea to adjust SVR2 to set the max current lower. If you turn it all the way clockwise, you should be at about 975mA at 10v input.

[quietstorm]

Ummmhhh...what's a bias resistor ?

[evilc66]

It sets the saturation current on the base of the transistor. Basically turns it on.

[quietstorm]

Evil, I have a question concerning the 10V "line" on the diagram. Can I hook up directly a 10V voltage power or I'd be better off with the schematics you posted earlier with the LM317 and the 10K pot ? Again, this is for a "P" model.

[evilc66]

Depends on the quality of the power supply used. It might be better to use a 12v supply and an LM317 like used with the "D" model, but use a 10K resistor instead of a pot to set the voltage.

[quietstorm]

Alright, following the schematics you posted, if I use a 10K resistor as R2 and 1,2K and 220 ohms as R1, it gives 10,05V output. Is that a problem considering that it's >10V ?

Also, do you have an example of a bias resistor, like a reference or a website ? I have no idea what it means in french and I can't find no equivalent ! I'm sorry !

Finally, could you please explain in a few words how the dimming works, especially the transistor and bias resistor thing ? The Arduino output seems to be 5V, how could it make a 0 to 10V variation ?

[evilc66]

Why not use a 1K and 470 ohm resistor to get just under 10v? I'd rather be on the safe side. Both resistors are common values.

A bias resistor isn't a specific product. It's just a resistor used to perform a specific function. All it does is set a current to drive the transistor.

Dimming for this driver is not analog 0-10v. It's pwm (pulse width modulation), which basically means that you turn the 10v on and off at varying rates to give the appropriate input signal. The Arduino is 5v, but that's what the transistor is for. You use the 5v signal to switch the 10v source on and off.

[evilc66]

Ok, here is something I made to aid in clarification for those trying to make the pwm circuit for the "P" models.



Black lines are component leads
Red lines are bottom side solder traces
Blue lines are top side wires

Use a 12v or greater (up to 32v) power supply for this.

[deepdvnarq]

thanks Evil!

now i really know where i went wrong. yahoo! i will still ave to wait for next week though but

THANK YOU!

[quietstorm]

Hello guys,

From what Evil and others have been writing here and there, here's a draft of my dimming circuit for a "P" driver, using a PWM signal coming from an Arduino.

What do you guys think about it (hope the upload is working) ?

Thanks in advance !

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[evilc66]

Perfect. You hit the nail on the head.

[quietstorm]

Great ! Would that be a problem if I used a PNP instead of a NPN transistor ?

Also, in some circuit design I've seen on other threads or websites, the load (the driver in that case) is between the collector and the 10V. In what is it different ?

[Sherman]

Ok, here is something I made to aid in clarification for those trying to make the pwm circuit for the "P" models.



Black lines are component leads
Red lines are bottom side solder traces
Blue lines are top side wires

Use a 12v or greater (up to 32v) power supply for this.

Waiting for this a long time.
Finally know hwere I go wrong

[evilc66]

Great ! Would that be a problem if I used a PNP instead of a NPN transistor ?

Also, in some circuit design I've seen on other threads or websites, the load (the driver in that case) is between the collector and the 10V. In what is it different ?

I goofed on that one. The difference is where you put the load. Actually, a PNP transistor is a better choice. On a PNP transistor, the load is on the emitter. On an NPN, the load is on the collector.

Waiting for this a long time.
Finally know hwere I go wrong

Yeah, I should have done this a long time ago

[Sherman]

I goofed on that one. The difference is where you put the load. Actually, a PNP transistor is a better choice. On a PNP transistor, the load is on the emitter. On an NPN, the load is on the collector.


Yeah, I should have done this a long time ago

Is that going to make any differences?Wheather the load is on the emitter or collector.Sori if it is a stupid question as I an not electronic train

And Thank You for sharing.Its better late then never

[quietstorm]

Why a PNP instead of a NPN ? And what reference do you suggest ?

[evilc66]

You could do it either way, but the PNP is a little easier, and potentially a little more reliable. With an NPN transistor, you would connect +10v to DIM+, then DIM- to the collector. the driver may not like being controlled from a switched negative setup. With a PNP, the emitter is connected to DIM+, and DIM- goes straight to ground. This is a switched positive setup and will be better suited for this application.

[Crazy Tiki]

Hey Guys,

I have the meanwell "D" drivers and wanted to build Evil's LM317 circuit to reduce a 12V power supply, but since I am not a EE I was wondering if someone could actually list weblinks for the proper parts.

[bxz]

I'm wondering if anyone can explain this.

I was experiencing the regular version ELN-60-48 on 13 crees, with an amp meter in series, the reading was 2.3A something when I plug in the power, and it didn't change, then I quickly turned the SVR2 down to about 850ma just in case all LEDs blew up. I also had experience on an ELN-30-24 with 6 crees where I can turn the SVR2 to make the current 400ma something.

Strange the 30-24 spec mentioned (-25% ---- 3%), for the 1.25A max, 400nm is more than -50%.
the 60-48 spec max current is 1.3A, how come it reaches 2.3A, I dare not to leave it long enough to see if it'll drop on its own eventually. And I'm sure my AMP meter is correct.

thx
BXZ

[quietstorm]

Alright, I've modified my PCB design. Is it better now ? I've found out that the PNP transistor 2N2907 is the complementary transistor for the 2N2222. What do you think about it ? Could I use it ?

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[evilc66]

Hey Guys,

I have the meanwell "D" drivers and wanted to build Evil's LM317 circuit to reduce a 12V power supply, but since I am not a EE I was wondering if someone could actually list weblinks for the proper parts.

All of that is available at Radioshack. Nothing special there.

Alright, I've modified my PCB design. Is it better now ? I've found out that the PNP transistor 2N2907 is the complementary transistor for the 2N2222. What do you think about it ? Could I use it ?

Your transistor symbol is upside down. Other than that it looks good.

Edited by evilc66, 09 November 2009 - 11:11 AM.

[artnsx]

I am going to be doing a LED conversion on my BC29 with 24 LEDS and 2 meanwell eln-60-48p drivers but there is only one part holding me back-- i can't understand the part about building a PWM circuit.

I understand the diagram in post #521 somewhat. I understand the concept of regulating the voltage from a power supply via the LM317. After reading up, I still have no clue what an arduino is. I just want to be able to turn the LED's on and off via a switch or a timer, and have a dial where i can adjust the voltage to the LEDs. Would there be a simpler circuit than the one above?

Would the V12 just a be a 12v wall plug power supply where the positive goes to the LM317 and the negative gets grounded?

As a side note, If I can't make any sense out of this whole thing, would an easier route be to just get the "d" version of the meanwells and then hook it up to a RKL with an ALC module?

Edited by artnsx, 11 November 2009 - 10:33 AM.

[Crazy Tiki]

I am going to be doing a LED conversion on my BC29 with 24 LEDS and 2 meanwell eln-60-48p drivers but there is only one part holding me back-- i can't understand the part about building a PWM circuit.

I understand the diagram in post #521 somewhat. I understand the concept of regulating the voltage from a power supply via the LM317. After reading up, I still have no clue what an arduino is. I just want to be able to turn the LED's on and off via a switch or a timer, and have a dial where i can adjust the voltage to the LEDs. Would there be a simpler circuit than the one above?

Would the V12 just a be a 12v wall plug power supply where the positive goes to the LM317 and the negative gets grounded?

As a side note, If I can't make any sense out of this whole thing, would an easier route be to just get the "d" version of the meanwells and then hook it up to a RKL with an ALC module?

You can wait for evil, but for your requirements I would recommend a "D" model and then you can build the more simpler circuit with standard radio shack parts, see above diagram, and be able to control the dimming. I have also read that you can also just buy a RKL and hook it up directly to the meanwells (you might want to ask evil how to do this exactly) bypassing the 10V circuit

The "P" models use a PWM signal to control the voltage which controls the dimming function (i think this is corret). The Arduno is a DIY programmable circuit or chip.

Edited by Crazy Tiki, 11 November 2009 - 10:46 AM.

[evilc66]

^^agreed. Much easier.