0-10 volt dimming

[Electric-Light]

150228-1325 EST

Electric-Light:

If all 0-10 dimmers have an internal voltage source, then what is used to control many fixtures as a group. I know ways to do it, but my question is what is normally done.

No, lighting dimmers do not have a voltage source. The dimming console is a variable load that sinks to a target voltage and the load applied is proportional to the number of fixtures. All the fixtures are connected in parallel and loaded down by a bus powered sinking voltage regulator. The number of fixtures allowed per control is limited by the sinking capacity of the control console.

The energy is dumped at the switch box. The sourcing capacity of each ballast is not allowed to be over 500uA and it is galvanically isolated from the power side to several thousand volts, as required by UL.

Some ballasts have a soft-off capability and might switch off under say 1v while some bottom out at the minimum dimming level. A short anywhere in the dimming circuit will pull everything to minimum or off state. This is why you need to ISOLATE the specific fixture and energize it with nothing connected to dimming wires. If the isolated fixture lights up, but everything else doesn't, the control wiring is crossed or shorted somewhere.

When you have violet and grey completely disconnected from suspected fixture and line voltage applied to white and black, but it still does not operate, then the driver/ballast/:lol: ED control box thingy is bad.

0-10v for THEATRICAL applications use a sourcing console and sinking luminaires. So, the dimming console needs a battery or an AC adapter to maintain galvanic isolation.

 

[Electric-Light]

Here's specs for Universal's dimming CFL ballast:

Dimming Control Specifications:
? 10 to 0 vDC Voltage Control
? 10v = maximum output
? Can be wired as Class 1 or Class 2 Circuit
? 0v = minimum output
? Ballast will source a maximum of 250uA for control needs
? Built-in line voltage protection circuit: Deep-dimming condition when line voltage is applied to control leads

So, what this is telling you is that if you were to apply line voltage to dimming control, it will throttle down to minimum output, but do not suffer damage. The specific behavior will depend on each control gear. It's possible that Light Emitting Decoration drivers will do the same, or become stuck at full output and capacitive coupling in 12/4 could be enough to make it act up.

 

[gar]

150301-1527 EST

Electric-Light:

I am going to descibe the information you provided above in the following way:

The 0-10 dimmer provides dimming control based the voltage at the 0-10 input terminals. 0 V equals full dimming, minimum light output. 10 V provides no dimming, maximum light output. This voltage can be generated any desired way.

Internally at the 0-10 input terminals there is a voltage or current source connected to the input terminals. If a voltage source, then there is a current limiting resistor providing a relatively high internal impedance to the voltage source. Suppose the voltage source is 20 V, then the current limiting resistor is R = 20*10^6/250 = 80,000 ohms to provide 250 microamperes of short circuit current. At 10 V there is 125 microamperes to power the the voltage regulator at the control console.

At the control console there is an active circuit to control the voltqge across the control wire pair to the 0-10 input.

Clearly you can supply an external voltage source to control this dimmer, but it must be able to sink at least 250 microamperes per dimmer connected to it.

With no external voltage source connected to the 0-10 input terminals there is a rather high input impedance to this input. Thus, noise sensitive. Since there may be active circuitry associated with this input my suggestion of a shunt 25 mfd capacitor may present some oscillation problems. But it is still worth a try.

.

 

[Electric-Light]

Internally, I do not know how the control voltage source is produced. It's gotta be magnetically or optically linked. All I know is that it's galvanically isolated from the power side.

The "dimmer" is the active variable resistance placed upon grey and violet.

The dimmable control terminals are a part of the ballast or light emitting decoration fixtures.

Does this clear things up for you a little bit?

 

[gar]

150301-2150 EST

Electric-Light:

Your drawing is fine as a rough illustration of the circuit. Where you show the adjustable resistor one can place an adjustable power supply and get the same result.

.

 

[Electric-Light]

150301-2150 EST

Electric-Light:

Your drawing is fine as a rough illustration of the circuit. Where you show the adjustable resistor one can place an adjustable power supply and get the same result.

.

And that's how 0-10v for theatrical applications work, but ballasts/Light Emitting Decoration power supplies designed for lighting applications are sourcing, so as far as we're concerned in the field, if they're not putting out volts, they're faulty and you need to replace them.

 

[ShaunRay]

If you want the 0-10V dimming for your LED, then you can simply achieve it using the variable resistors called PT by connecting it in the series. Also you can try the SCR and TRIAC. These both are the voltage controlled devices similar like Transistor but both has huge difference. It will be efficient and cheap if you can use the SCR or TRIAC.

 

[ShaunRay]

You can simply use the Potentiometer to control the voltage across your LED. It is very simple to use resistor based device. Also you can go for the SCR or TRIAC. These both are the Transistor like devices but having different functions. It will be efficient and cheap if you use the SCR or TRIAC.