9V battery eliminator circuit for car

| | ,

9V battery eliminator circuit for car, sometimes you need a 9 volt battery to power some circuit, the problem is that sometimes we don’t have them on hand, or if it is a scheme that requires a little more current, the battery will discharge quickly. Then we could use rechargeable batteries, but the issue is that they are expensive. So, it is better to use a voltage converter circuit as shown here.

The IC used is the 78L08 voltage regulator, which has a low quiescent (quiescent) current and provides enough current to replace a 9-volt battery. The voltage regulator IC 7809 even exists, but the 7808 is easier to find, for voltage to be close to 9 ‘volts’ we use the diode 1n4148 in the ground terminal of the IC, so we will have 8.7 volts that replaces a 9-volt battery quietly. The circuit input has an LC filter and an RC filter. These filters eliminate disturbances coming from the power supply network.

Nowadays, it is easy to find the 78l09 and in this case, the diode D2 (1n4148) can be removed, and a jumper added on the spot.

It was added the suggestion of printed circuit board and reduced size, can be installed in the same place where it would go 9V battery or even the board can be installed in the box where the cells of the 9V battery would be. Simply make the connections using an input connector and connecting a 9V battery clip to the output.

Get new posts by email:
Follow us on social media

The 78lxx family IC normally supports up to 100mA of current, see the datasheet for more details.

If you prefer you can also use other voltage regulators like LM78L33 (3.3V), LM78l05 (5V), LM78L62 (6.2V), LM78L82 (8.2V), LM7812 (12V), LM7815 (15V). The maximum input voltage is 30V, depending on the manufacturer, check the datasheet of the voltage regulator IC.

Depending on the voltage regulator used you can use it to power various battery or battery-powered electronics, 3V (2 batteries), 5V (3 batteries), 6V (4 batteries), 8V (5 batteries), 9V (9V battery or 6 batteries). Just pay attention to the maximum current of 0.1A.

To power the circuit we will use any DC source up to 30V and 500mA or more, diode D1 serves to protect against reverse polarity.

Circuit diagram 9V battery eliminator circuit for car

Circuit Diagram 9V Battery Eliminator Circuit For Car
Circuit Diagram 9V Battery Eliminator Circuit For Car

Printed Circuit boar for Circuit diagram 9V battery eliminator circuit for car

Pcb, Printed Circuit Board For 9V Battery Eliminator Circuit For Car
Pcb, Printed Circuit Board For 9V Battery Eliminator Circuit For Car
Pcb, Printed Circuit Board Component View For 9V Battery Eliminator Circuit For Car
Pcb, Printed Circuit Board Component View
Pcb, Printed Circuit Board Component Silk For 9V Battery Eliminator Circuit For Car
Pcb, Printed Circuit Board Component Silk

BOM  to assemble the 9V battery eliminator circuit

PartValorDescriptionQuantity
Capacitors
C1, C2, C3100n (104)Capacitor ceramic3
C4100uF/16Capacitor electrolytic1
Miscellaneous
CN1INDC Input1
CN2OUTRegulated output1
Semiconductors
D11N4004Diode1
D21N4148Diode (optional)1
IC178l0978l09 voltage regulator1
LED1led 3 mmLed 3 mm red1
Resistors and inductors 1/4W
R1820 ohmsGray, red, brown, gold1
R210 ohmsBrown, black, gold, gold1
L1, L210uHBrown, black, gold, silver2
Semiconductors
Solder, Wires, PCB, Box, power supply

Download the files, PCB in PDF, PNG and Gerber. Includes panel with 6 boards per panel.

Download

Mirror

Lm78l09 IC Datasheet PDF

How useful was this post?

Click on a star to rate it!

Average rating / 5. Vote count:

No votes so far! Be the first to rate this post.

As you found this post useful...

Share on the social networks!

We are sorry that this post was not useful for you!

Let us improve this post!

Tell us how we can improve this post?

Previous

Circuit custom power supply for audio amplifier – Symmetrical

lm2756 Ni-Cd and NI-MH Battery charger circuit

Next

Leave a Comment