How can i raise the current of circuit for drive a solenoid ?

Projects General Guidance
1

Hi all,

I have 12V 17W solenoid valve, power supply is 12V 8.5A , TIP35C darlington and of course Arduino Uno.

I tried 'the standart solenoid circuit with arduino' and solenoid triggered but valve didn't close and then i checked the current of solenoid is nearly 500mA.

After that i drove only solenoid with power supply. everything is ok and the current of solenoid is 1A.

i think my solenoid needs 1A or higher. What should i do for fix this situation?

Thanks in advance.

sketch1.jpg
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2

Use an external power supply rated at the voltage and current needed for the solenoid.
See these examples:

.

3

i'm using external power supply. Arduino powered by 9V 1A adapter. The circuit powered by 12V 8.5A.

p.s : i cannot reach your attachment . could you refresh it? Thanks.

4

SirAcar:
...

p.s : i cannot reach your attachment . could you refresh it? Thanks.

Larry's image is a jpeg at http://i.imgur.com/f5nBHpB.jpg. Just go to that address to see his file. He doesn't need to refresh anything.

5

The Darlington may be dropping 1.5V, so the solenoid is not getting the full 12V.

Try using a logic level MOSFET such as stp36nf06l instead of the Darlington.

Don't forget to connect a flyback diode across the solenoid terminals to short any reverse voltage when the solenoid is stitched off.

6

Hi,
Vce(on) is 4V, so big volt drop.
Can you replace your base resistor 1K with 150R, it will give you more base current, as Vbe(on) is 2V.

But you would be much better with a MOSFET.

Tom.. :slight_smile:

7

i'm trying immediately :slight_smile: thanks.

8

i tried 150R . it still triggered but valve didn't close again. i measured the current is 960mA and then i tried no resistor . the problem is still going on.

i used only valve and power supply such as manually, the current is 1A and valve working perfectly..

how can i fix this problem?

i am writing components again :

12V 17W solenoid valve, TIP35C transistor, 12V 8.5A power supply, flyback diode, 1K or 150R resistor for base.

are you any suggestion for components? ( I can make a component change because this project will be an industrial project.)

9

SirAcar:
...and then i tried no resistor.

A TIP35 (not a darlington) is a poor choice.
It needs a base current of 100-150mA for that solenoid, and has a high (~2volt) saturation drop.
How long do you think the Arduino will last by trying to force that base current from a 20mA Arduino pin.

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Leo..

10

Hi,
As PaulRB suggested in post #4.
A MOSFET will have much lower ON resistance and dissipate less power.

Solenoid2.jpg
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Tom.... :slight_smile:

11

thank you all. i'm trying mosfet circuit.

i can't find stp36nf06l in my country.

Do you have any suggestion to replace stp36nf06l ?
i didn't use a mosfet before so what are the appropriate parameters for mosfet of this project?

Kubi :slight_smile:

12

SirAcar:
i can't find stp36nf06l in my country.

...what are the appropriate parameters for mosfet of this project?

Then state your country. Maybe we can find a suitable one for you.

Logic level, N-channel.
Leo..

13

N-channel, logic level, low Rds, low gate capacitance.
Make sure it has good current flow with Vgs = 4.5V. Some claim to be logic level, but current is only 250uS (0.25mA) at Vgs = 4.5V.
Like this series of parts:

Unfortunately Digikey stops carrying them on me! This board uses 32 of them - I started with AOI518, then AOI514, then AOI510, will be ordering AOI508 next time I order parts. Getting ready to ship 21 cards to South Korea that will use most of the last batch of parts I ordered.
http://www.crossroadsfencing.com/BobuinoRev17/

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