[[email protected]]

Hi guys.

I have a music keyboard that didn't come with a power supply. You must
supply your own. The keyboard requires 200mA of 9V DC power.

I have a power supply that allows you to change the voltage & polarity
but it is listed as 1000mA.

Can I use this power supply with the keyboard? What would happen if I
did?

Thanx 4 looking.

 

[Trevor Wilson]

Hi guys.

I have a music keyboard that didn't come with a power supply. You must
supply your own. The keyboard requires 200mA of 9V DC power.

I have a power supply that allows you to change the voltage & polarity
but it is listed as 1000mA.

Can I use this power supply with the keyboard?

**Probably.

What would happen if I

did?

**It would probably work just fine, as long as you get the polarity right.

However, you should ensure that the new power supply is a 'regulated' type.
An unregulated supply is likely to potentially cause damage.

 

[jasen]

I have a power supply that allows you to change the voltage & polarity
but it is listed as 1000mA.

Can I use this power supply with the keyboard? What would happen if I
did?

if you set it to 9V it should work well, as long as the polarity is correct.

Bye.
Jasen

 

[Trevor Wilson]

if you set it to 9V it should work well, as long as the polarity is
correct.

**Before you provide advice like this, I suggest you get hold of an
UNREGULATED power supply and measure the output at 20% of maximum. You will
be in for a Hell of a shock.

 

[[email protected]]

The supply is an Archer for Tandy. I've had it for over 10 years(?).
It makes no mention of un/regulated on it's markings.

 

[Trevor Wilson]

The supply is an Archer for Tandy. I've had it for over 10 years(?).
It makes no mention of un/regulated on it's markings.

**Then it will be unregulated (with 99% probability), as regulated supplies
are almost always marked appropriately. I advise you not to use it, unless
you can check the output Voltage. An unregulated supply can typically
deliver 30% - 50% higher Volts, when operating at reduced load. That may
cause damage to the connected equipment. A regulated supply will remain
within reasonable tolerance (better than 10%) from zero to full load.

 

[jasen]

**Before you provide advice like this, I suggest you get hold of an
UNREGULATED power supply and measure the output at 20% of maximum. You will
be in for a Hell of a shock.

those adjustable ones are usually pretty good.

Bye.
Jasen

 

[Trevor Wilson]

those adjustable ones are usually pretty good.

**The regulated ones are fine. The unregulated ones are ALL hopeless at
dealing with varying loads. And the OP wants to run the device at
significantly less than the designed load of the supply.

 

[[email protected]]

**Then it will be unregulated (with 99% probability), as regulated supplies
are almost always marked appropriately. I advise you not to use it, unless
you can check the output Voltage. An unregulated supply can typically
deliver 30% - 50% higher Volts, when operating at reduced load. That may
cause damage to the connected equipment. A regulated supply will remain
within reasonable tolerance (better than 10%) from zero to full load.

OK, I won't risk it.

Thanx 4 the heads-up.

 

[[email protected]]

While we're on the subject. I have an old discman. Next to the power
input it says DC9-12V with a negative tip. It doesn't however list the
amps. Why is this? Does the ampage(?) not matter with this device?

 

[Trevor Wilson]

While we're on the subject. I have an old discman. Next to the power
input it says DC9-12V with a negative tip. It doesn't however list the
amps. Why is this?

**It probably will, somewhere. Certainly, the instruction manual will tell
you.

Does the ampage(?) not matter with this device?

**It matters. However, given the range of input Voltages, it is possible
that an unregulated supply will work OK. Personally, I would always use a
regulated supply. The cost difference is minimal.