Vixen centre negative question

[woldsman]

I’ve managed to source a Vixen SD-1 controller. It comes with an adapter with a cigarette  lighter style plug. I know Vixen SD-1 handsets are centre negative. If I try and power it from the mains using a 12v cigarette lighter to mains adapter plug (pictured), will the circuit still be centre negative? Electronics are not my thing and I don’t want to find out it is centre positive the hard way! Advice much appreciated. 

[Peter Drew]

I'm no expert but I do know that original Vixen handsets were centre negative.  Maybe things have changed since but they were only protected to 1 amp so great care must be taken.  A friend used to have a handy little pocket money side line in repairing and adding better protection to Vixen handsets.  I have used cigarette cables on centre positive equipment with no problems.       🙂

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[Franklin]

No and don't use any 12v supply for it, you'll fry it. They run off 9vDC centre negative, if you haven't got the original battery pack, you can get, off Ebay, a 5vDC USB step up lead which converts a USB powerbank into 9vDC centre negative. These leads are intended for use with electric guitar pedals like BOSS pedals which are made in Japan and are 9vDC centre negative. These leads cost less than a fiver and then you can run your SD-1 from a rechargeable USB powerbank, 10,000mAh works best and will power your scope all night long off a single charge. 

USB 5V to 9V 5.5x2.1mm USB to 9V Power Supply Cable for Guitar Effects Pedals | eBay

I hope you read this before you plug the Halfords in! It will tick over on tracking at 12v but as soon as you use the fast forward button the circuit will overheat, do so at your peril!

Edited March 9 by Franklin

[woldsman]

1 hour ago, Franklin said:

No and don't use any 12v supply for it, you'll fry it. They run off 9vDC centre negative, if you haven't got the original battery pack, you can get, off Ebay, a 5vDC USB step up lead which converts a USB powerbank into 9vDC centre negative. These leads are intended for use with electric guitar pedals like BOSS pedals which are made in Japan and are 9vDC centre negative. These leads cost less than a fiver and then you can run your SD-1 from a rechargeable USB powerbank, 10,000mAh works best and will power your scope all night long off a single charge. 

USB 5V to 9V 5.5x2.1mm USB to 9V Power Supply Cable for Guitar Effects Pedals | eBay

I hope you read this before you plug the Halfords in! It will tick over on tracking at 12v but as soon as you use the fast forward button the circuit will overheat, do so at your peril!

Thanks, Franklin! I've not plugged ANYTHING in yet.

[woldsman]

On 09/03/2024 at 14:08, Franklin said:

No and don't use any 12v supply for it, you'll fry it. They run off 9vDC centre negative, if you haven't got the original battery pack, you can get, off Ebay, a 5vDC USB step up lead which converts a USB powerbank into 9vDC centre negative. These leads are intended for use with electric guitar pedals like BOSS pedals which are made in Japan and are 9vDC centre negative. These leads cost less than a fiver and then you can run your SD-1 from a rechargeable USB powerbank, 10,000mAh works best and will power your scope all night long off a single charge. 

USB 5V to 9V 5.5x2.1mm USB to 9V Power Supply Cable for Guitar Effects Pedals | eBay

I hope you read this before you plug the Halfords in! It will tick over on tracking at 12v but as soon as you use the fast forward button the circuit will overheat, do so at your peril!

Hi,

The adapter’s arrived, ordered from the link. I decided not to risk running off mains powered usb and used a battery usb power pack. The controller lit up red. So I turned it off again quickly. The D battery pack lights up the sd-1 handset as green.

Any comments - red must be bad, I guess.

Simon

[crush]

Hi

Don't know if it would help and I do not have the controller that you are talking about but I use a bench PSU to power everything with a cigarette lighter adapter, you can wire it centre positive or negative and set the voltage and amps to what ever you need. 

[Cosmic Geoff]

I recommend you get a multi-test digital meter (available cheaply online) and use it to test the polarity and voltage of any supply BEFORE you plug it into any Vixen device. e.g.

Neoteck Multimeter Pocket Digital Multi Tester Voltmeter Ammeter Ohmmeter AC/DC Voltage Current Resistance Diodes Transistor Audible Continuity with Backlight LCD for Factory and other Social Fields: Amazon.co.uk: DIY & Tools

[Franklin]

8 hours ago, woldsman said:

I decided not to risk running off mains powered usb and used a battery usb power pack. The controller lit up red. So I turned it off again quickly. The D battery pack lights up the sd-1 handset as green.

Any comments - red must be bad, I guess.

I've had a number of SD-1 controllers and some have had red, others green lights. I think it's just a power indicator light and I've never had a problem when using it when red. Could be more to it though, I guess?

[woldsman]

18 hours ago, Cosmic Geoff said:

I recommend you get a multi-test digital meter (available cheaply online) and use it to test the polarity and voltage of any supply BEFORE you plug it into any Vixen device. e.g.

Neoteck Multimeter Pocket Digital Multi Tester Voltmeter Ammeter Ohmmeter AC/DC Voltage Current Resistance Diodes Transistor Audible Continuity with Backlight LCD for Factory and other Social Fields: Amazon.co.uk: DIY & Tools

Agreed - I need to get one of these and learn how to use it!

[crush]

Really easy to use, the photo on the link shows it set at 20v direct current which will be a good starting point. Black lead to negative red to positive, if you get it the wrong way round it would just read with a minus in front of the voltage on the screen.

[woldsman]

On 23/03/2024 at 21:16, Cosmic Geoff said:

I recommend you get a multi-test digital meter (available cheaply online) and use it to test the polarity and voltage of any supply BEFORE you plug it into any Vixen device. e.g.

Neoteck Multimeter Pocket Digital Multi Tester Voltmeter Ammeter Ohmmeter AC/DC Voltage Current Resistance Diodes Transistor Audible Continuity with Backlight LCD for Factory and other Social Fields: Amazon.co.uk: DIY & Tools

Hello - a follow up query. As will become obvious, I don’t know what I’m doing.

I ordered the Neoteck multimeter. Before using it, I read up on safety. Seems like the key thing is always to insert the black probe first.

Testing the D battery pack, I got a positive voltage reading of 27.4. See the attached image. Reversing the leads, I got a reading of -0.000. I’m concluding this indicates center positive? If so, 27v seems way too high. Although the handset lights up green (indicating the sd-1 is center positive?) I’m concerned the voltage may be too high with the battery pack.  However, there are eight 1.5v batteries so I don’t understand why the reading is not 12v. Even this is on the high side as 9v has been cited as the correct input.

I’ve also no idea how to test the polarity and voltage of the usb powered lead as this has a single pin and although there are two electrodes at the end there is insufficient space to insert both probes.

[Stu]

50 minutes ago, woldsman said:

Hello - a follow up query. As will become obvious, I don’t know what I’m doing.

I ordered the Neoteck multimeter. Before using it, I read up on safety. Seems like the key thing is always to insert the black probe first.

Testing the D battery pack, I got a positive voltage reading of 27.4. See the attached image. Reversing the leads, I got a reading of -0.000. I’m concluding this indicates center positive? If so, 27v seems way too high. Although the handset lights up green (indicating the sd-1 is center positive?) I’m concerned the voltage may be too high with the battery pack.  However, there are eight 1.5v batteries so I don’t understand why the reading is not 12v. Even this is on the high side as 9v has been cited as the correct input.

I’ve also no idea how to test the polarity and voltage of the usb powered lead as this has a single pin and although there are two electrodes at the end there is insufficient space to insert both probes.

It looks like you have the multimeter set to AC rather than DC. If you rotate the selector switch anti clockwise five clicks you should be on 20V DC so should get an accurate reading.

[crush]

Hello

First thing is your multi meter is set to AC current that is what the two wavy lines mean. The straight line with the dashes underneath is for direct current. this will be why your reading is off.

For testing your lead, if you mean the one at the edge of your photo the outside of the plug is one of the terminals.

[Carbon Brush]

Yes the meter is set to AC voltage.
As an aside. When an AC range is selected and a DC supply is connected, many meters show zero volts.
Basically telling you there isn't any AC!
This meter displays about double the DC value leading to confusion.
I won't go into the (mostly cost saving) reasons behind this strange response.
V-straight line is DC. Batteries, mount power supply output, etc.
V~ squggle is for alternating (AC) supplies. That is (dangerous) mains and transformers.

[woldsman]

6 hours ago, Stu said:

It looks like you have the multimeter set to AC rather than DC. If you rotate the selector switch anti clockwise five clicks you should be on 20V DC so should get an accurate reading.

Thanks!  New reading is 12v. Now I need to understand which way around is the correct probe arrangement. Gut feeling is black on the left and red on the right. ie the black & white wire is neutral. This gives center positive from the D battery pack.

Edited April 4 by woldsman

[woldsman]

On 24/03/2024 at 16:12, crush said:

Really easy to use, the photo on the link shows it set at 20v direct current which will be a good starting point. Black lead to negative red to positive, if you get it the wrong way round it would just read with a minus in front of the voltage on the screen.

Thanks - only just read your message!

[woldsman]

6 hours ago, crush said:

Hello

First thing is your multi meter is set to AC current that is what the two wavy lines mean. The straight line with the dashes underneath is for direct current. this will be why your reading is off.

For testing your lead, if you mean the one at the edge of your photo the outside of the plug is one of the terminals.

Thanks - inserting the black probe into the step up lead pin and the red probe to the side, the reading is +9v. Another centre positive reading? I thought the step up lead for guitar pedals were center negative. Also unclear why the hand set lights up red when the 9v step up lead is used but green when the 12v battery pack is used. A few things to ponder…

[woldsman]

OK so I tested an adapter for a household applicance plugged into the mains supplying 14v. Black probe in the pin and red probe on the side. The reading was -14. On the plug itself there is printed a minus in a circle, a C sign and a plus in a circle. So it is centre positive. Conclusion: the red probe goes in the pin and the black probe touches the side. That gives 14v the correct result. So the 12v battery pack and 9v step up lead are both center negative. 
 

No idea why the “on” light is red when the 9v step up is used. As Franklin comments, may not matter.

Edited April 4 by woldsman

[Stu]

5 minutes ago, woldsman said:

OK so I tested an adapter for a household applicance plugged into the mains supplying 14v. Black probe in the pin and red probe on the side. The reading was -14. On the plug itself there is printed a minus in a circle, a C sign and a plus in a circle. So now I’m thinking that a minus sign on the readout denotes centre positive, in which case both the 12v battery pack and the 9v step up are centre negative.  Confusing!

Normal centre positive means putting the black probe on the side, and red probe in the centre part should give a positive reading. If it is centre negative then you would get a negative reading.

The symbols are as in these diagrams:

[crush]

Hi @woldsman found this on line that may help

http://www.vixenamerica.com/pdf/Control/VixenNorthAmerica_DD_1_Controller_Voltage.pdf

[michael8554]

If that is the correct D-cell pack for the mount, you have proved that a centre positive supply is needed.

Michael

[Cosmic Geoff]

12 hours ago, woldsman said:

OK so I tested an adapter for a household applicance plugged into the mains supplying 14v. Black probe in the pin and red probe on the side. The reading was -14. On the plug itself there is printed a minus in a circle, a C sign and a plus in a circle. So it is centre positive. Conclusion: the red probe goes in the pin and the black probe touches the side. That gives 14v the correct result. So the 12v battery pack and 9v step up lead are both center negative. 

You still appear a little confused by meter use. As a former electronics engineer, I find it hard to put myself in the position of someone who has no clue about electrics. However, your appliance PSU above appears to be centre positive.   If the meter indicates positive, then whatever the red lead is contacting is positive.  When testing such plugs, it will be less confusing if you always touch black to outer and red to pin, so that centre positive leads indicate (+) and centre negative leads (-).

If you have any round batteries (e.g. AA) lying around, test them with your meter.  The flat end is always negative, and the domed end positive.

[woldsman]

Thanks for all the replies. Everything is now resolved. Summarising:

The SD-1 handset is centre NEGATIVE.

It can run from a 9v step up lead which in the UK is manufactured for electric guitar pedals. 
When testing with a multi meter, set to DC (V followed by a solid line symbol above a dotted line) with a range up to 20.

Put the red (positive) probe in the centre of the small pin and the black (neutral) probe to the side of the pin to obtain a result.

The SD-1 handset when turned on lights up green but if power is low (for example when running from a battery) it lights up red warning of low power.

Edited April 5 by woldsman

[michael8554]

7 hours ago, michael8554 said:

If that is the correct D-cell pack for the mount, you have proved that a centre positive supply is needed.

Michael

My Bad, I misread that you were testing the round plug on the battery pack.

 

Michael