12 volt DC to 9 volt AC

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
OK, did a search, didnt come up with anything. I'm wondering how hard/easy it will be to make something that can convert 12 volt DC to 9 Volt AC. It needs to be fairly regulated and clean, as its for a piece of audio equipment, but not super sensitive like a computer.

What im doing is trying to use an Alesis Nanoverb in my car. It has a 'wall wart' power supply of 120 volt in and 9 volt AC out. Not sure what frequency AC out. Im assuming 60 hz. I dont really think using a 12 volt to 120 volt setup up inverter will work that well. Maybe thres another component that has 12 volt DC input... hmm. Any thoughts?
 
Hi, It is a litle tricky converting DC to AC. Part of the process involves injecting a square wave or sign wave into the signal to create alternating current.

If I were you I'd rather find the DC powersupply in the component you are trying to connect, and attach a regulatd DC supply there. Actually depending on how accessible the DC supply is in this device, you might either attach an unregulated stepped down DC source after the rectifier or a regulated DC supply of the right value after the regulator circuit.

If you are looking to experiment, consider using a 12VDC to 120VAC step-up converter. Take care in considering the current limitations on the converter. However considering the powersupply is a wall wart, an inexpensive ~$30USD converter might work.

Good luck,

-David
 
You could probably get away with a 9V regulator followed by a mosfet full bridge. Run the full bridge from a 60Hz oscilator. The result would be a 9V square wave. This should be fine for the Alesis since its only going to convert back to DC anyway.
 
Why mess around trying to make AC. My guess, and it's just a guess, is that the 9VAC goes to a bridge rectifier and then a filter cap. That combination will give about 12 VDC. You could just input 13 VDC with a little over 1.2 volts for diode voltage drop every thing will be fine. I've done this sort of thing lots of times and unless there is some internal need for the AC signal it will work great.

Do check out to make sure that the 9 VAS goes straight to the bridge or the power switch and then the bridge, if so your home free.

Later BZ
 
HDTVman said:
Why mess around trying to make AC. My guess, and it's just a guess, is that the 9VAC goes to a bridge rectifier and then a filter cap. That combination will give about 12 VDC. You could just input 13 VDC with a little over 1.2 volts for diode voltage drop every thing will be fine. I've done this sort of thing lots of times and unless there is some internal need for the AC signal it will work great.

Do check out to make sure that the 9 VAS goes straight to the bridge or the power switch and then the bridge, if so your home free.

Later BZ

I have taken appart similar Alesis gear before, and the bridge is not connected directly to the power input socket. There are some caps in series with the bridge to prevent a DC power supply from working. The supply must be AC or it will be blocked by the caps.
 
ClassD said:


I have taken appart similar Alesis gear before, and the bridge is not connected directly to the power input socket. There are some caps in series with the bridge to prevent a DC power supply from working. The supply must be AC or it will be blocked by the caps.

That's why I suggested that the power input be checked out before just trying the 12 VDC input.

It's possible that Alesis is using a voltage doubler type of circuit to get + / - supplies and that would require an AC input.

Later BZ
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.