pedalectric

Batteries & power distribution

One easy solution to usuing 12v power in audio systems is to step it up to mains voltage with an inverter, and then use standard mains amplifiers. In some ways this would be greener, as it would be possible to use an unmodified existing amplifier system, if you already had one. But:

efficency - in stepping up and down, power is lost - that's wasted pedalling.

safety - low voltages (below 50v) are a lot safer to work with, particularly in oustide, potentially damp conditions. This also reflected in safety legislation - less that 50v means fewer requirements.

We do not offer mains power for performer's equipment. This isn't a problem as we can normally find a solution in advance - we can provide an amplifier for bass & guitar, and even a [midi] keyboard if necessary. We also reserve the right to allow mains powered equipment near our system, and will refuse to provide power for a mains inverter.

Batteries:

main battery shown above - note blade fuses (all inputs & outputs fused, bar the lower three outlets which share a fuse - normally used for lower power equipment), ammeter (showing current in & out), bulgin input connectors and canon output connectors. terminal posts with 4mmm sockets included for unexpected requirements. ;-)

our smaller battery - one input, one output and 4mm sockets. This has a single in-line fuse between the connections and the battery - with the disadvantage that if it blows, the unregulated generator voltage works stright into the load. To be replaced by two - one for input, one for output...

Power input to batteries: Bulgin 8-pin connector. This is Nick's standard generator connector, and compatibility has proved very useful when we've found ourselves borrowing gear... ;-) It is a standard connector for disco mains lighting, though; whilst it is unlikely you're likely to have a live mains lighting system with a pedal generator system, care should be taken of the two are in proximity.

Power distribution: Canon 4-pin XLR connector. This is actually a broadcast standard for 12v power; p1 is used for 0v, p4 for 12v. XLR connectors are rated at 10A per pin, so for amplifiers which take higher currents we connect p1 & p2, and p3 & p4. The have the advantage that they cannot be connected incorrectly (polarities reversed, and it is also not possible to connect two power sources together) and also lock together, avoiding cables falling out.

The car cigarette lighter connector is often used on 12v equipment, often built in (in particular power supplies, phone chargers and the like); they are are also useful for compatibility, allowing equipment to be used in a car if necessary. We don't fit them as standard on batteries or elsewhere as power outlets, as if left live, if something metal falls into them they could easily short out the system. We use 4 pin XLR adapters to cigarette lighter outlets where required.

It is important, when connecting powered equipment together, to the audio earth is connected to a consistant point voltage-wise. If powering a mixer from the internal inverter within an amplifier, it is possible that the audio earth is complete disassociated with the 12v supply rails. As soon as 12v powered equipment is connected, this changes, so it is worth defining the audio earth as being the negative side of the 12v supply. This tends to be default, but should always be checked, particularly with step-down power supplies for CD players and the like.

Power input to batteries: Bulgin 8-pin connector. This is Nick's standard generator connector, and compatibility has proved very useful when we've found ourselves borrowing gear... ;-) It is a standard connector for disco mains lighting, though; whilst it is unlikely you're likely to have a live mains lighting system with a pedal generator system, care should be taken of the two are in proximity.
Power distribution: Canon 4-pin XLR connector. This is actually a broadcast standard for 12v power; p1 is used for 0v, p4 for 12v. XLR connectors are rated at 10A per pin, so for amplifiers which take higher currents we connect p1 & p2, and p3 & p4. The have the advantage that they cannot be connected incorrectly (polarities reversed, and it is also not possible to connect two power sources together) and also lock together, avoiding cables falling out.
The car cigarette lighter connector is often used on 12v equipment, often built in (in particular power supplies, phone chargers and the like); they are are also useful for compatibility, allowing equipment to be used in a car if necessary. We don't fit them as standard on batteries or elsewhere as power outlets, as if left live, if something metal falls into them they could easily short out the system. We use 4 pin XLR adapters to cigarette lighter outlets where required.