Par 36 (Pin Spots)

[ThomJ]

This is a stupid question but I cannot find anyone who seems to know

 

How many amps does a single 30w 6v Pin Spot draw.

 

The Normal WAV formula dont work(=5amps), as the unit has a transformer.

 

How do tranformers affect the WAV calculation. :)

[Mush]

This is a stupid question but I cannot find anyone who seems to know

 

How many amps does a single 30w 6v Pin Spot draw.

 

The Normal WAV formula dont work(=5amps), as the unit has a transformer.

 

How do tranformers affect the WAV calculation. :)

<{POST_SNAPBACK}>

 

Watts is always Watts, is worth remembering, something that pulls 30w at 6V will be pulling 30W at 240V apart from Transformer efficiency.

 

Lets guess the transformer is 90% efficient, so 10% gets lost as heat. so your 30W lamp is effectively drawing 33W from 240V.

 

P =I/V

 

33/240= 0.1375 A call it 0.14A for handyness or at 110V

 

33/110 = 0.3A

[Pete Alcock]

Thom,

 

For all intents and purposes you can treat a transformer as 100% efficient in a case like this. Power in (Watts) = Power out (Watts).

 

So on the low Voltage side of the transformer you have a 30W bulb on 6V drawing, as you rightly say, 5A. On the mains side it's consuming 30W of power at 230V so the current draw is 30/230 = 0.13A.

 

It'll be a bit higher than this actually because the transformer isn't 100% efficient (it gets warm).

 

Pete.

 

Sorry - Mush must've posted whilst I was still writing.

[Andrew C]

You may already know this, but I'll add it just in case... Unless you are sure of your dimmers ability to dim inductive loads - don't. You'll trash the transformers, and while they can be replaced it's a bgr of a job!

[Flyingwysiwyg]

You may already know this, but I'll add it just in case... Unless you are sure of your dimmers ability to dim inductive loads - don't.  You'll trash the transformers, and while they can be replaced it's a bgr of a job!

<{POST_SNAPBACK}>

 

Or if you are unsure, you can add a resistive load (a load lamp) into the circuit (such as a PAR can back stage with some 119 on the front)

 

F - Wyg

[Andrew C]

You may already know this, but I'll add it just in case... Unless you are sure of your dimmers ability to dim inductive loads - don't.  You'll trash the transformers, and while they can be replaced it's a bgr of a job!

<{POST_SNAPBACK}>

 

Or if you are unsure, you can add a resistive load (a load lamp) into the circuit (such as a PAR can back stage with some 119 on the front)

 

F - Wyg

<{POST_SNAPBACK}>

Tried that, still killed 'em off! May be the JTM dimmers I'm still using!