Converting 12VDC to 9VDC

[Guy Lavoie]

What about using zener diodes to drop the voltage? Cheap and easy?

Zeners are used to get a reference voltage but rarely as the regulator itself, unless the current draw of the load is very small (less then a quarter amp). This is because as a regulator, it needs to be in parallel with the load, and sinks current from the source through a current limiting resistor until the voltage is at the right value. Thus you need to figure out what series resistance is needed to drop the voltage to just a bit more then the load needs, and the zener diode "eats" the extra current that brings the voltage down to the right value. Without a series resistor (or with too low a value), the zener diode will try to sink too much current and burn up.

 

[Digger]

Guy Lavoie,

I agree that anything more then a quarter to half amp is impractical to use a zener. I thought some of the devices mentioned were very low current.

 

[electron]

FY, the W800RF32 uses about 20mA@9VDC.

 

[rocco]

FY, the W800RF32 uses about 20mA@9VDC.

So the extra heat generated, if you power it from 13 volts, will be .08 watts. Not-a-lot.

 

[CollinR]

I have like 100+ listings for just these distributed 12VDC power supplies, none of them 30 or 50 amps though!!! Thats alot of current man.

Anyway if you guys get tired of your wall worts shoot me an email/PM, if the can color is an issue to you (blue/tan/grey/black) make sure and let me know. Same goes if you prefer a fuse (you can limit however you like) or auto reset breakers (usually 800ma 12VDC). Also have rackmount supplies for the guys who use 19" racks instead of cans.


Wall worts suck! 1st way to tell a professional install from a hack job. Everyone should have one.

 

[noshali]

I have like 100+ listings for just these distributed 12VDC power supplies, none of them 30 or 50 amps though!!! Thats alot of current man.

Anyway if you guys get tired of your wall worts shoot me an email/PM, if the can color is an issue to you (blue/tan/grey/black) make sure and let me know. Same goes if you prefer a fuse (you can limit however you like) or auto reset breakers (usually 800ma 12VDC). Also have rackmount supplies for the guys who use 19" racks instead of cans.


Wall worts suck! 1st way to tell a professional install from a hack job. Everyone should have one.

Do you have this stuff up on your website??

regards,

 

[CollinR]

Not at this time, up until here recently I have been against internet sales.

I know I won't maintain all of the products I can get, so even if I did put some up for cocooners it would be what I consider most common.

Even though my prices are competitive pricing isn't my focus, the design and service are my focus. This is why I have been against internet sales, most are only after the lowest price, you can't have the best products and service and the lowest price. 2 out of 3 isn't bad though.


Seriously if you know what you want just PM me,

ie.
UL Listed 12VDC 4 amp, 8 fused outputs in a beige can
UL Listed Dual 12VDC/24VAC 4amp/4amp 16/16 outputs in a black can
UL Listed 24VAC 16amp 32 output in a 4U rackmount


You may well see some stuff up on my site here before long but you'll always get the best deal if you buy a package or system from me personally and mention cocoontech.com (PM is obvious).

Collin