Power supply downgrade

[SparkyCal]

I have a 9 volt power supply that plugs into the wall and produces 9v DC.

Is there any way that i can make it into a 6V power supply. Is it possible to put a resistor before the 9v end, and make it into a 6 v end?

 

[Harald Kapp]

Is it possible to put a resistor before the 9v end, and make it into a 6 v end?

Only under very special circumstances. Welcome to Ohm's law: V = I*R. Voltage drop across the resistor depends on load current, therefore your output voltage will vary wildly from 9 V without load to 0 V with a heavy load.
What you need is a voltage regulator.

 

[bertus]

Hello,

As @Harald Kapp said, a voltage regulator will do a better job as a resistor.
You can use a LM7806 , a LM317 with some adustment resistors or a LD1117-adj with the adjustment resistors.

Bertus

 

[SparkyCal]

Harald and Bertus

Thanks for the info. It is times like these that i realize just how much have to learn. I looked at the schematics. I don't have the parts, and it may be a little beyond my skill level at the moment.

I was hoping it might as easy as placing a resistor in line with the wire that comes out from the transformer unit that plugs into the wall.

I have a ton of adapters that plug in the wall. Many of them produce 12vDC. 9v dc, 5 Vdc. You'd think i'd have one that produces 6V Dc, but I don't ;-(

 

[bertus]

Hello,

You could use some of these boards:
https://www.amazon.ca/Converter-Cir...ctronics&sprefix=lm317,electronics,228&sr=1-1

If that is even to difficult, perhaps a power adapter like this is something for you:
https://www.amazon.ca/Belker-Univer...r+adapter&qid=1590502472&s=electronics&sr=1-3
The output voltage can be selected.

Bertus

 

[SparkyCal]

I have one of those in the house somewhere. problem is, i can't find it ;-)

 

[Martaine2005]

What are you trying to power with 6v?.
There are many situations that over voltage or under voltage will work just fine.
Some Circuits have a working input voltage of between 3-18 volts.
Some 6v circuits will be quite happy with 5 volts.
If there is a regulator in circuit, the input voltage will (should) add the necessary overhead voltage for driving the circuit.
By the way, this doesn’t mean you can use a higher voltage suppply ‘willy nilly’.

Martin

 

[SparkyCal]

It’s a deer cam. Designed to snap pictures and take short videos when motion is detected

 

[Martaine2005]

I can’t say specifcally, but most cams that I have are powered by 9-12 volts.
If yours specifies 6volts, try a 5 volt usb power bank first.
You might be surprised how well it works.

Martin

 

[dave9]

If it is meant to use 4 x alkaline batteries and that is how you arrived at 6V, odds are very good that it would work at 5V.

However, there may be something you can do, depending on the design of the PSU. If it's a switcher and has just a fast silicon diode after the transformer, you could swap in a schottky and gain maybe 0.3V, which isn't a lot, but if your cam is borderline with 5.0V, surely 5.3V is close enough to 6V. If it it would have had terrible battery life, if only able to drain each cell down to 1.33V. Then again if you are using a long wire run to power it, you might have some voltage drop from that distance unless a suitably low wire gauge is used.

However, since as I suggested above, I suspect this is set up to run from a somewhat variable power input as the batteries drain, I would do something cruder if you don't have a voltage regulator. Instead I'd use the 9V PSU but put 4x silicon diodes in series on the output which will drop about 2.5V, leaving you with 6.5V, and a "little' margin for voltage drop from the wire.

However I would test this first. I mean that diode Vf drop decreases with a decrease in current so if this cam is idling at very low power draw, it could cause the resultant voltage to rise. Certainly a voltage regulator is the safer choice if you don't want to do (more, since you must still confirm proper operation) testing, but on the other hand, mains AC power is inexpensive and this must not consume much, for the lower power state you could use a resistor between positive and ground to pull the float voltage down some, or a zener diode to clamp it. Then again, IC linear or buck voltage regulators are not hard to find, nor expensive.

 

[SparkyCal]

I think it runs on 8 1.5 AAs

 

[dave9]

^ Then is it putting pairs of cells in parallel, how did you arrive at 6V as the target?

 

[Bluejets]

Buck converter Ebay $2.00.....

https://www.ebay.com.au/itm/DC-DC-B...778794?hash=item2ac67e17aa:g:UmgAAOSwfHBcgNPH

 

[Audioguru]

Eight AA cells might be used to produce +6V and -6V.

 

[narkeleptk]

Harald and Bertus

Thanks for the info. It is times like these that i realize just how much have to learn. I looked at the schematics. I don't have the parts, and it may be a little beyond my skill level at the moment.

I was hoping it might as easy as placing a resistor in line with the wire that comes out from the transformer unit that plugs into the wall.

I have a ton of adapters that plug in the wall. Many of them produce 12vDC. 9v dc, 5 Vdc. You'd think i'd have one that produces 6V Dc, but I don't ;-(

the 780x are insanely easy to set up. You can get by with just Vin (9v) > cap - 7806 - cap - and get your Vout (6v).
I'm not sure the value's you'd want for the caps prob anything would work fine. maybe go with .1uf or what ever you have available..