Center Pin Polarity Check?

[vestaviascott]

I've been buying and selling lots of used fitness equipment recently. It often happens that the power adapters are missing and the ones that have option to run off batteries are usually missing the battery cover.

Ultimately, I end up purchasing a matching adapter for each unit prior to selling, however, just for checking the consoles pre-purchase, I think it would be helpful to have a "Universal" power adapter on hand.

I've picked up one of these power adapters and it has removable tips that can be rotated to match the device's center pin polarity. However, without a manual for each device, what are the means to determine the polarity on site? I understand this specific device is limited to 2.1amps.

[vestaviascott]

Re: Center Pin Polarity Check?

Maybe this question could be better phrased:

"Can the barrel/pin be checked with a multimeter to determine center pin polarity?"

[budm]

Re: Center Pin Polarity Check?

You cannot tell the DC input jack polarity of the device without taking the device apart to be 100% sure unless it is printed on the device, and if the device is well built with protection, it should be able to protect itself from damage due to wrong polarity connection.

[vinceroger69]

Re: Center Pin Polarity Check?

i would use a multi meter and use ground on one of the boards then test center or outer pins on the socket the main thing with that type of adapter does it provide enough amps?

[vinceroger69]

Re: Center Pin Polarity Check?

You cannot tell the DC input jack polarity of the device without taking the device apart to be 100% sure unless it is printed on the device, and if the device is well built with protection, it should be able to protect itself from damage due to wrong polarity connection.

what sort of amps on the adapter would these bikes use the one linked is 1.3amp is that enough?

[vestaviascott]

Re: Center Pin Polarity Check?

...the main thing with that type of adapter does it provide enough amps?

The machine calls for 6v 2a power supply. The universal connector can output up to 2.1 amps.

i would use a multi meter and use ground on one of the boards then test center or outer pins on the socket

In the field (aka "thrift shop") I can't easily take the machines apart to ground to one of the internal boards. Is there an alternative for ground? One lead on center pin the other on outer barrell, take a resistance reading?

[budm]

Re: Center Pin Polarity Check?

Always use the adapter that has at least 20% more current capability than the device requires.

[budm]

Re: Center Pin Polarity Check?

The machine calls for 6v 2a power supply. The universal connector can output up to 2.1 amps.




In the field (aka "thrift shop") I can't easily take the machines apart to ground to one of the internal boards. Is there an alternative for ground? One lead on center pin the other on outer barrell, take a resistance reading?

I would do the research online to find out what the original power supply is capable of and it should also have polarity printed on the power supply itself. BTW, some of them may use AC output instead of DC, that is why you need to do research first.
BTW, the center pin of typical 5.5 mm barrel may be 2.1mm or 2.5 mm so you need to verify that also since 2.5mm of the adapter will fit into 2.1mm pin but it will not make proper contact.

[vinceroger69]

Re: Center Pin Polarity Check?

how i read that is the usb outlet is up too 2.1 amps?

[vestaviascott]

Re: Center Pin Polarity Check?

what sort of amps on the adapter would these bikes use the one linked is 1.3amp is that enough?

In this case, its an elliptical machine that also takes 4 D batteries:



It calls for a 6v 2a adapter which I'm trying to replicate with the universal adapter.

The battery cover is missing so I can't easily connect the batteries, although I suppose I could use two wires to series connect both sets of batteries as the cover would otherwise be doing?

[budm]

Re: Center Pin Polarity Check?

how i read that is the usb outlet is up too 2.1 amps?

That is correct. It is only rated at 1.3A (1300mA) @ 3 ~ 12V! as printed on the package.
2.1A for USB.

[vinceroger69]

Re: Center Pin Polarity Check?

thanks budm i wasnt 100% sure if i was reading it correctly

[vestaviascott]

Re: Center Pin Polarity Check?

That is correct. It is only rated at 1.3A (1300mA) @ 3 ~ 12V! as printed on the package.
2.1A for USB.

Frick! I didn't catch that! So, maybe the battery hack? Just connect two wires to each pair of batteries? Just for testing the console temp.

[vinceroger69]

Re: Center Pin Polarity Check?

for testing joining the batteries will work but if soldering wires on watch the heat as batteries can explode.

[budm]

Re: Center Pin Polarity Check?

Frick! I didn't catch that! So, maybe the battery hack? Just connect two wires to each pair of batteries? Just for testing the console temp.

You can solder wire to each pair of batteries and try.

[vestaviascott]

Re: Center Pin Polarity Check?

That is correct. It is only rated at 1.3A (1300mA) @ 3 ~ 12V! as printed on the package.
2.1A for USB.

So, if the machine specifies 6v 2a and I try to use a 6v 1.3a power supply (aka the "universal" adapter above), it may or may not work or it definitely will not work?

[vestaviascott]

Re: Center Pin Polarity Check?

You can solder wire to each pair of batteries and try.

I may just tape the wires to the batteries. Its just to confirm the panel is working or not at this point before I invest in a proper matched power adapter and battery cover.

[mariushm]

Re: Center Pin Polarity Check?

The polarity is usually printed on the label or engraved in the plastic near the dc jack

you should see a logo similar to this near the connector:



majority of connectors these days have the negative on the outside and positive in the center. In older machines, sometimes the positive was on the outside because this was made it easier to disconnect internal batteries when the adapter was plugged in ...

in your particular case, I'm not sure that universal adapter would be suitable. The thing uses D batteries, which are designed to be able to output a significant amount of current, more than what regular AA batteries can provide. So either the machine used D batteries for very long life (unlikely) or the machine really does require that 2A of current (or gets close to that ammount)
So your 1.3A max adapter may not be enough to run the machine properly - at some points, if the machine pulls more than 1.3A , the adapter may reset or turn itself off, or the voltage could drop below some threshold.

On the other hand, you have 4 D batteries, and this means the product has to account for batteries going low... new batteries would be 1.5v..1.65v for alkaline batteries while empty batteries would probably go down to around 1.35v..1.4v ... so the product may actually work with around 4 x 1.3v.. 1.35v = 5.2v .. 5.5v

if your choice isn't good enough, you should test with a usb charger designed for max 2a, it may be able to power your machine even if the voltage is less than 6v

[vestaviascott]

Re: Center Pin Polarity Check?

The polarity is usually printed on the label or engraved in the plastic near the dc jack

you should see a logo similar to this near the connector:

That would certainly make it brain dead simple, but there is no such diagram to be found. That's why I'm asking how to test the polarity without that diagram to guide me.

if your choice isn't good enough, you should test with a usb charger designed for max 2a, it may be able to power your machine even if the voltage is less than 6v

The machine has a barrel type connector. How would I connect a USB charger to it?

[budm]

Re: Center Pin Polarity Check?

Why don't you just try with batteries first just to see the if the machine is even working instead of discussing on how to use your universal power supply to power up this bike.