power supply

[johhny b bad]

Hi there, new member so go easy please. I have a Yamaha keyboard and I'm thinking of doing some busking. Right, the 240v transformer I have for my keyboard has an output of 12v dc @ 1600mA. Q can I connect the keyboard directly into something such as a car battery? Only reason I'm asking is, I dont want to make a lead up to do this if the first time I plug it in, the keyboard goes up in a puff of smoke. As the keyboard is only drawing a max of 1600mA and I know a car battery can deliver up to 32A. Do I have to have something else between the battery and the keyboard to reduce the amps? Stupid question I know, but I'm a wood butcher by trade really and electrics is a bit of a mystery to me . Thanks

John B

 

[riotmaster]

Welcome along fellow new member! Yeah if the transformer is Max 1.6 amps, you want a fuse ideally between 1 and 1.6, though not up on my car fusing sizes! I know you can get 1 and 2 amp fuses, so go for one amp and see how you get on. Are you planning on taking a car battery with you while busking?

 

[ian.settle1]

Welcome along fellow new member! Yeah if the transformer is Max 1.6 amps, you want a fuse ideally between 1 and 1.6, though not up on my car fusing sizes! I know you can get 1 and 2 amp fuses, so go for one amp and see how you get on. Are you planning on taking a car battery with you while busking?

If he tries to use a supply of 1 amp it will not last very long.

He requires a PSU that will give at least 2 amp output so it is not overloaded.

 

[riotmaster]

Yeah but he was talking about using a car batt or something giving out 32a, hence the fuse down. A 12v Psu would obviously need a min 2a rating, but if he was using a psu wouldn't he need a 230v supply, therefore using his transformer and making this post pointless?

 

[johhny b bad]

Hi thanks for the reply. What I want to know is can I connect just the keyboard up to something like a car battery (not the PSU) I know that the PSU requires a 240v supply but would need a very long extension cable from my house to where I'm thinking of going LOL. FYI the keyboard has a socket on the back that the low side of the PSU plugs into. The transformer supplies this at 12v DC @ 1600mA. I know I could use an inverter to convert 12v DC into 240v Ac but dont want to go down that route. all I want to know is as the keyboard itself takes 12v DC can I connect just the keyboard to some sort of battery that supplies 12v DC ?

 

[boatnik1]

You can connect it up directly to the car battery with no problems but preferably with a 2A fuse on the + wire.
Check your power supply to see if the center pin is + or - and connect the car battery the same way. Even if you connected it the wrong way round there should be a diode in the keyboard which will protect it. It's just if you connect it the wrong polarity it just wont work. The keyboard will only use the current it needs regardless of the car battery capacity. Incidently a car battery can deliver over 700 amps for starting cars, not 32.

 

[DPG]

Fully charged car battery will have terminal voltage of around 13.5V (roughly). Now this probably won't damage your keyboard but there is a risk. You need a 12V regulator. Maplin sell car power supplies which plug into the car cigarete lighter and give switched voltages, eg 6/9/12V out. Connect a cigar lighter socket to your battery and plug this into it, jobs a gud 'un. Daz