Dimmer has 0-10V input, how to effectively steer it?

[AL13N]

I have a dimmer that has 0-10V input.

It basically has basically 5 contacts:

• L & N: the 230V AC
• X with circle, so, the light (i put the other end of a regular bulb light to the N)
• +Y and -Y , so that's the 0-10V input

So, i have a 12VDC 50W supply nearby, so i'm trying to use it.

Doc says <1 it's in standby and then from 1 to 10 it's active; shortcut, overvoltage : makes it disabled and overtemp will also disable.

of course, since the powersupply is 12V , that's too much, and i don't actually want to give it full power anyway.


I tried making a simple voltage bridge with 2 equal resistors, cause 6V is a good starting point, but it did not give the correct voltage, it seems the +Y and -Y inputs have weird effects on the simple voltage bridge...?

the weird thing is, that I measured the loose +Y and -Y and it seems like unconnected there's 11,35V over it?

So, then i thought, wait, maybe i just need to put a resistor (potentiometer) on it, since it already has a voltage... but then i got negative voltage??? and the more resistance i put on it, the more negative the voltage went...

I'm puzzled on how this even works?

In the end i measured resistance of +Y and -Y when it's off and i got 22k, so I put a 22k resistor on my 12V line and put the +Y on the other end, and the -Y on the 12V and i measured the +Y at 18.3V which means the diff between +Y and -Y is 6.3V and that sort of works.... and here i'm also puzzled as to why it measures at 18.3V and not at 6V, and how the hell this even works...

Could anyone help me understand how this works?

 

[ChrisP58]

Please provide a schematic or drawing of what you're doing. It's difficult to follow what you're saying.

 

[rjenkinsgb]

Also, check the documentation for whatever dimmer it is - it may be non-isolated so the control circuit also needs to be floating (& possibly could be live).

That could certainly explain the strange effects with the power supply!

 

[schmitt trigger]

Try a 9 volt battery

 

[AL13N]

Also, check the documentation for whatever dimmer it is - it may be non-isolated so the control circuit also needs to be floating (& possibly could be live).

That could certainly explain the strange effects with the power supply!

Yeah, the documentation was not too clear on that, it has multiple settings and each of those settings are explained, but nothing about the input except that it's the 0-10V dimming control...

I do suspect that the 0-10V input does have some kind of non-isolation, my question is kind of 2-fold:

• is there a way of things i could check to see how it would work, what kind of testing i could do to figure some things out?
• how to effectively "guard" against it? "floating" you call it? At first i was thinking, if i used 2 high-ohm resistor, it would have less effect, but then when i thought about it, that just does not work at all, cause any much smaller load in parallel to one such resistor will make the total resistance much lower and skew the voltage anyway; then i thought i could use a very low resistor, but then i'd just up the amps and have huge power leaks... How does one make an output more impervious to whatever it's connected to? a power supply clearly seems to manage that well enough...

 

[ChrisP58]

Can you post a link to the dimmer itself, and it's documentation?

 

[gophert]

This is a VERY COMMON LED constant current with dimming supply.

DO NOT CONNECT A VOLTAGE TO IT.

it is called 10v but, oddly enough, one is a current source and the other is current sink. Add a 5k (typical) pot across the two wires and connect the pot's wiper to one of the other two. At min, the LEDs will be off, at max, measure the voltage across. If less than 10v, use a bigger pot (10k).

some work backwards - full brightness at no resistance across the pot and dim at about 5k.

If the you want bright/dim the other way, move the wiper connection to the other pot terminal.

 

[KeepItSimpleStupid]

Here https://www.trcelectronics.com/ecomm/pdf/hlg40h.pdf is documentation for a 1-10V dimmer and basically you can;t get to 0% without adding parts. Here https://www.trcelectronics.com/View/Mean-Well/IDLC-25A-500.shtml is one that does do dim to off. The latter one with the AUX 12V supply has some hiccups like it's not always there.

Note they play games with 2 in one or 3 in one dimming. PWM, 0-10/1-10, resistance.

Let's just say with a potentiometer input, dimming more than one module isn;t going to happen.

1-10, 0-10V has this problem with off. This has impedance issues.

PWM is easy to isolate.

Some allow resistance dimming too.

Eventually, I will have to deal with this issue with a 40W lamp that I want to dim. It's a mogel base corn cob lamp and about 6000 lumns.

 

[KeepItSimpleStupid]

I tried making a simple voltage bridge with 2 equal resistors, cause 6V is a good starting point, but it did not give the correct voltage, it seems the +Y and -Y inputs have weird effects on the simple voltage bridge...?

In order to adequately size say a potentiometer for this application, you need to know the input impeadance of the dimmer. Even the seoond power supply I linked to doesn;t have the spec. Anideal voltage source is supposed to have a zero output impeadance.

An easy way of measuring it is to have a voltage source e.g. 9V battery and insert a variable series resistor. Measure the 9V source and then adjust the potentiometer so the voltage is 1/2 the value. Then take the potentiometer out of the circuits and measure R. That will be the input Z of the dimmer. A 9V battery also has an ESR or effective series resistance which can likely be ignored.

You may have to "build" a circuit. Generally you would select a single supply "rail to rail" , unity gain stable. OP-amp. Rail to rail means it gets really close to 0V and really close to 12V, but you need close to 0 and close to 10 V with a 12V input. An easy way is to get a reference IC and buffer it with an OP amp and then feed the end of a 10K potentiometer. Then use another OP-amp to buffer the wiper to get a really close 0-10V reference. You can use a 2.5, 5 or 10V reference and add some gain. The offset voltage of the OP-amp gets amplified too.

Just picked this https://www.st.com/en/amplifiers-and-comparators/tsb712.html this out of a hat. The lowest voltage it can reach is 200 mV with a single supply and within 200 mV of your 12V supply. There is a wierd IC somewhere that can generate a slightly negative supply from a positive supply, so it includes zero.

The LM324 might be a better choice. https://www.ti.com/lit/ds/symlink/l...l-digikeymode-df-pf-null-wwe&ts=1604969979475 The lowest voltage it can output is 20 mV max and it can get within 1.2V of the 12V supply. The offset voltage is higher.