13 Volts AC in a car?

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

mackinthebox

Member
Joined 2010
How can convert 12VDC to 13VAC?
Im integrating an amplifier into my dash and pretty much sealing the whole thing up so it cant be stolen
all you will see will be a volume knob, a couple RCA jacks (i may even hide those...) and maybe some VU meters if I can figure out this AC power thing...

ive got a VU driver board but it requires 13VAC
I thought about just installing a small inverter for 110vac and plugging the power supply into that but that would take up alot of room and just doesnt seem clean enough

anyone have any ideas?
 
sofaspud

sofaspud

Member
Joined 2005
AC18~24V according to the board.
What is the black component between the 2 green terminal blocks in the first picture? Can you give us a part number?
I'm thinking this thing has onboard rectification to DC. I'd bet the rent on it.
Is that a TO220 LM7812? If so, you can just tap in there with your car's DC.
 
P

Perry Babin

Member
Joined 2003
bcae1.com
If the AC is rectified into a single positive rail, you may be able to feed it DC. 18v of AC will give you about 25v of DC (which is what you'd want from what's shown on the datasheet for the IC). You could get 25v DC from rectifying the AC on the primary of one of the amp's power supplies.

If the power supply needs to be isolated from ground. You could get the power from the same source but you'd have to run it through a small transformer (which you could wind yourself).

It's likely to be a single-ended supply since there aren't two identical rail capacitors.
 
theAnonymous1

theAnonymous1

Member
Joined 2004
14xlpz.jpg
 
theAnonymous1

theAnonymous1

Member
Joined 2004
You can find 2W dual output 12V DC-DC converters on e*ay for $15. They are extremely small and would probably be the easiest solution. Just run the outputs in series for 24V.

The VU driver IC could run directly from the converter, or if it's an 18V regulator on the board, power the regulator from the converter (better noise filtering?).
 
M

mackinthebox

Member
Joined 2010
awesome! thanks for all the info guys
I just woke up a little while ago and just got to work :p

here is the reply i got from the fleabay seller

Hi,

Yes, it can be operate with DC.This can be achieved by injecting DC 28V directly to the 7824 regulator, or the two connections of the filtering capacitor. Make sure the polarity is correct otherwise the capacitor and the regulator chip will be destroyed.

Best Regards,
JIMS AUDIO
Click to expand...

Im going to look into getting a power regulator, ive seen several on ebay that have adjustable output and can use the car voltage source input

thanks again for all the info!
 
M

mackinthebox

Member
Joined 2010
I was looking at one of these, $7.90 on ebay:
DC to DC Module based on LM2577 Step-Up (Boost) Regulator

Non-Isolated Step-Up Module

LM2577 Non-isolated Step-up DC-DC Module
Input Voltage: DC 3.7~30 V
Output Voltage: DC 4~32 V ( adjustable, O/p Voltage >I/p Voltage by 1.23V )
Maximum Input Current: 3 A ( 25W ,Under normal circumstances please 2.5A Current )
Maximum Output Current: 2.5 A
Efficiency: 86 % , Max 92 %
Module Properties: Non-isolated step-up module (BOOST)
Full Load temperature rise: 45°C
No-load Current: Typical 15mA (5V switch 12V)
Load Regulation: ± 0.5%
Voltage Regulation rate: ± 0.5%
Dynamic response speed: 5% 200uS
Short-circuit Protection : None
Input Reverse Protection: None
Operating Temperature: Industrial (-40°C to +85°C)
Size: 43 x 30 x 18 mm (L*W*H)
 
M

mackinthebox

Member
Joined 2010
Perry Babin said:
You can rectify the primary switched DC on any of the power supplies in any of your amps to get ~28v DC. The circuit below produces about 27v with 13.5v input to the amp.
Click to expand...

I dont have any amps in my truck anymore
everything was stolen a couple months ago and im still in the process of replacing them

Ive got myself a little tripath TA2020 amp that I will be installing in the dash and I will be covering the hole where the stereo was located and making sure it just looks like nothing is there

on another area of the dash I will have my volume knob and the VU meters
thats about all you will see and it will appear to be built into the dash where it cant be removed

when I eventually get subs again they will be chained to the cargo tie downs either with actual chain or some steel cable so they cant be easily stolen
the amp will be hidden in the fender well where the jack hangs out

this way if it actually does get stolen my insurance will cover it more easily as they have been permanently installed ;)
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Top Bottom