Daisy Chaining AC Power?

**Bryan R. Tyler** · #1 09-24-2009, 11:33 AM

Never tried this before, so I figured one of you could tell me it was safe before I blew something up. I got a second Boss VF-1 (again) and they each run on 800mA of 14v AC power- I figured I could get one of those 3 amp 14v laptop adapters and just use a daisy chain to power them both. Safe?

mward69 · #2 09-24-2009, 11:41 AM

Quote:

Originally Posted by Bryan R. Tyler

Never tried this before, so I figured one of you could tell me it was safe before I blew something up. I got a second Boss VF-1 (again) and they each run on 800mA of 14v AC power- I figured I could get one of those 3 amp 14v laptop adapters and just use a daisy chain to power them both. Safe?

I don't think that would be safe....the 800mA is a fraction of a 3 amp power supply. Amp ratings is the killer as far as electrical goes. As an example, you have a 10 amp device, and you put it on a 100 amp breaker...it's designed to trip when overloaded...we'll since it has 100 before it kicks..the wires or device will burn up.
if you have a few pedals, either build a small pedalboard, or just setup a system with a GOOD power strip..and go to a local Radio Shack and get the adapters...they are pretty cheap.

wayshot · #3 09-24-2009, 12:24 PM

Only if your laptop adapter is AC. Pretty much all laptop adapters I've seen are DC, so it probably wouldn't work.

JustOpenYourMind · #4 09-24-2009, 12:29 PM

Quote:

Originally Posted by mward69

I don't think that would be safe....the 800mA is a fraction of a 3 amp power supply. Amp ratings is the killer as far as electrical goes. As an example, you have a 10 amp device, and you put it on a 100 amp breaker...it's designed to trip when overloaded...we'll since it has 100 before it kicks..the wires or device will burn up.
if you have a few pedals, either build a small pedalboard, or just setup a system with a GOOD power strip..and go to a local Radio Shack and get the adapters...they are pretty cheap.

You are right if you are talking about protection devices such as breakers and fuses.

For power supplies, a 3A supply simply means it can ''provide'' up to 3A of charge.

What you really need to know is if your Boss VF-1 really runs on 14V AC, usually most pedals run on DC so most if not all power supplies provide DC.

**Bryan R. Tyler** · #5 09-24-2009, 12:48 PM

Quote:

Originally Posted by wayshot

Only if your laptop adapter is AC. Pretty much all laptop adapters I've seen are DC, so it probably wouldn't work.

Funny- almost all the laptop adapters I've seen/owned are AC

Quote:

Originally Posted by JustOpenYourMind

You are right if you are talking about protection devices such as breakers and fuses.

For power supplies, a 3A supply simply means it can ''provide'' up to 3A of charge.

What you really need to know is if your Boss VF-1 really runs on 14V AC, usually most pedals run on DC so most if not all power supplies provide DC.

It's an older rackmount unit, not a pedal, and I'm sure it runs on 14v AC. I've had one for years.

bongomania · #6 09-24-2009, 02:07 PM

Quote:

Originally Posted by mward69

I don't think that would be safe....the 800mA is a fraction of a 3 amp power supply. Amp ratings is the killer as far as electrical goes. As an example, you have a 10 amp device, and you put it on a 100 amp breaker...it's designed to trip when overloaded...we'll since it has 100 before it kicks..the wires or device will burn up.

That's only if the device is designed in such a way that it will draw excessive current through components that can't handle it. If there is no low-potential draw on the output side of a device, the high potential at the input won't send in excessive current. Well-designed equipment will only draw as much current as it needs. All that "3 amp" rating means is the potential to draw up to 3 amps--it does not cause 3 amps of current to be "shoved into" the device, and 3 amps won't be drawn in unless there is some very low potential at the output.

**Bryan R. Tyler** · #7 09-24-2009, 02:11 PM

Those 1600mA 1-Spots would be far less popular otherwise

niftydog · #8 09-25-2009, 12:38 AM

There's no real difference between AC and DC in the context of daisy chaining. The main thing to work out is what the devices draw - they might be powered by 800mA adapters but chances are that they draw far less than that. Provided you're not trying to feed 2.5A down wires that aren't designed for it you'll have no issues.

A laptop power supply with an AC output does seem unusual to me. Perhaps consider buying a 14VAC transformer and building a custom enclosure for it.

**Bryan R. Tyler** · #9 09-25-2009, 06:36 AM

I think I'm getting them confused with my monitor adapters- I've got a few in a bin that I thought were for our laptops, but it sounds like I'm confusing them with another set. I'm just trying to save a little room as the standard Boss BRC adapters are each a big wall wart with 6' of power cable attached, and a single adapter with a 1' cable would be preferable.

4StringsEnough · #10 09-25-2009, 07:41 AM

Quote:

Originally Posted by mward69

I don't think that would be safe....the 800mA is a fraction of a 3 amp power supply. Amp ratings is the killer as far as electrical goes. As an example, you have a 10 amp device, and you put it on a 100 amp breaker...it's designed to trip when overloaded...we'll since it has 100 before it kicks..the wires or device will burn up.
if you have a few pedals, either build a small pedalboard, or just setup a system with a GOOD power strip..and go to a local Radio Shack and get the adapters...they are pretty cheap.

This is inaccurate as has already been pointed out. ALWAYS get more power than you need. To have too little power will cause damage. The device(s) will only draw as much power as they require and no more. More power also means that, at a given output, the power supply is not working as hard so won't be so prone to noise and/or overheating. Much like running a 1000W amp head at volume 2 - it gives you 'headroom'.