How to use a ROHM BA07CC0T for a newbie

[Stevequad]

Hello, I am trying to power an Arduino using this Fixed output regulator, where the power input is 19.5v 700ma from a wall wart. I want to send 7v to the arduino, and before the regulator circuit, I need the input power to also momentarily trigger a 12 volt solenoid. (12 to 20v) How do I configure this BA07CC0T? I can figure out the solenoid power input. I am new to this, and only do a few project in a decade, I do not understand ohms law or math equations to figure out electronics. I have tried to google help, but can not find the answer.
Thank you for any help.
Steve

Here is the data sheet if needed: https://www.electro-tech-online.com/custompdfs/2013/06/baxxcc0t_series-e-210264.pdf

 

[BioniC187]

Ok. For the solenoid. Do you have a multimeter? Measure the resistance of it. We can then use that to work out components for the activation of it.

The regulator - on page 4 of the datasheet in your post, you can see the pin numbers. line them up to your regulator, and connect them as it states in the table. Another thing you should do is have a cap connected from the input supply to ground, and then from the output supply to ground. so go to your local electronics place, and ask for a 474 ceramic capacitor, and a 10uf electrolytic capacitor.

You can then proceed to connect the 474 in any orientation from input supply (the+ve from the 19.5V. aka. pin 1 to pin 2) then connect the +ve terminal of the 10uf capacitor, from pin 3 to pin 2

 

[Stevequad]

BioniC187, Thank you for this information, it is great...The solenoid measures 9.6Ω. I was planning to use an optoisolator, or an N channel MOSFET, NTD4963N-1G. The opto is easy for me, as I have used them before. The Mosfet I was going to wire as follows,
the source pin to ground on both the Arduino, and the 19v, the gate to the Arduino pin to activate the circuit, and the +19v to the Drain pin on the MOSFET. What is your opinion on this part. (I was guided)
Although the solenoid is 12v, I am not really worried about hitting it with 18v for the fraction of a second that it will be active. Do you think it might cause a problem?
Thanks for the help, it is very much appreciated.

 

[Stevequad]

Well...I tried to fire the solenoid using an optoisolator, and it did not work. The one I was using was AQW280EH (data sheet: https://www.onlinecomponents.com/datasheet/aqw280eh.aspx?p=10550340&Resource=1) can anyone tell me what I have done wrong? I had center pin of wall wart, 19v to solenoid, ground of wall wart to opto pin 7 and ground of solenoid to opto pin 8. I am sure the opto was working, I put my meter on to dbl check continuity when it was on. I thought this would be easy for me, because I have used the same circuit to fire my flash, and also trigger my cameras.
The power supply is 19.5v 700ma.

 

[BioniC187]

ok. first things first. your power supply isn't going to cut it.

If you solenoid had 12V activation voltage, and at 9.6Ω, your current draw is 1.25A. Your psu is rated at 700mA.

so best thing here is to get a psu with 2A or so rating.

Also hitting your solenoid with 18V isn't a good idea. coz at 18V it will have 1.875A current draw. We rather not have the extra current draw - its precious

Your opto is rated at 0.36A peak load current. It won't drive your solenoid(is it blown now?). I suggest a relay to drive your solenoid.

What is the solenoid for? i'm asking coz maybe there can be a cheaper solution in terms of current. and where will the trigger for the solenoid come from? from the Arduino?

If you can, make a little drawing of your circuit etc, and upload it.

 

[Stevequad]

The solenoid is for water droplet photos. Activation is via push button, a pot will determine the timing between droplets. with the pot all the way 1 way, only 1 pulse is perceived,(it is actually 2 but only 1 is perceived) turning it to the left give it a double pulse, and sets timing between pulses. Another device controls the camera and flash's, and is working fine.
Pot is connected to pin A2, 5v, and g. L.E.D. is to pin 9 and g, and pin 4 is set to fire solenoid. A push button at pin 5.
The solenoid and PSU is what I have, and I wanted to keep my costs down. The Opto is not blown. But I thought I would just give it a try, and if it did not work, then use an N-Channel MOSFET, ON Semi NTD9463N-1G to fire the solenoid. The ROHMBA07CC0T, and ON Semi NTD9463N-1G are still in the mail, I don't have them yet. I will wire up the BA07CC0T per your instructions, then wire the ON Semi as: Source pin to Gnd on psu and arduino gnd, The Gate of MOSFET, to arduino pin 4 with a 200Ω resistor, The 18v to the Drain pin of the MOSFET. Nothing is set in stone, and I am very open to suggestions and help. I know you said the PSU was ??? but I would like to use it if at all possible.
I do appreciate the help you have given me. It is valuable, and I will use it, and learn.
Steve

Here is the sketch I am using:
/*
* Pushing a button
* turns on and off a light emitting diode(LED) connected to digital
* pin 9 and solenoid valve on pin 4. The amount of time the between
* LED blinks on and off depends on delay value, and
* the value obtained by analogRead() from a potentiometer at pin 2.
*
*
*
*/

#define BUTTON_PIN 5
#define VALVE
#define STANDBY 0
#define ACTIVE 1

int potPin = 2; // select the input pin for the potentiometer
int ledPin = 9; // select the pin for the LED
int valve = 4; // select the pin for the valve
int val = 0; // variable value coming from the pot

int mode = STANDBY;

void setup() {
pinMode(BUTTON_PIN, INPUT);
pinMode(ledPin, OUTPUT); // declare the ledPin as an OUTPUT
pinMode(valve, OUTPUT);
}

void loop() {
if (digitalRead(BUTTON_PIN) == HIGH)
{
mode = ACTIVE;
delay(750); // delay after button is pushed
val = analogRead(potPin); // read the value from the sensor this command can be removed
digitalWrite(ledPin, HIGH); // turn on LED
digitalWrite(valve, HIGH); // open valve
delay(10); // adjust to keep valve open for droplet size
digitalWrite(ledPin, LOW); // turn the LED off
digitalWrite(valve, LOW); // close valve
delay(val); // stop the program for delay value
val = analogRead(potPin); // read the value from the sensor
digitalWrite(ledPin, HIGH); // turn on LED
digitalWrite(valve, HIGH); // open valve for second droplet
delay(10); // adjust to keep valve open for droplet size
digitalWrite(ledPin, LOW); // turn the valve off
digitalWrite(valve, LOW); // close valve
delay(1000); // stop the program for delay value
}
}

 

[BioniC187]

Alright. the solenoid, is it an electronic water valve? if you want to keep the psu, you will have to change the solenoid, for one that has a lower rating. is there datasheet for the part?

 

[Stevequad]

BioniC187, yes it is a water valve. And...I got it to work using the ROHMBA07CC0T regulator, and ON Semi NTD9463N-1G MOSFET. Thanks for the tips on hooking up the regulator. I have it all transfered to a PC board, and put in a project box. Now with a push of the button (wired remote) the LED flashes, and the valve pulses. When I get the camera set up I can adjust the timing for collision drops via the POT.
Thanks for all your help.
Steve

 

[BioniC187]

Well that's great . I didn't do much tbh lol. Can you post some of your pics that you have taken with this feature? I'm intrigued by photography

 

[Stevequad]

I will do that..I am just getting started with drop shots.
Steve

 

[Stevequad]

My first shot at droplet collisions

This is my first attempt at collision drop photography, using the Arduino laser trigger, and the solenoid controlled by arduino with help from this forum member BionC187.
I know they lack some sharp focus, but it is a start. My smugmug photo gallery:

**broken link removed**

Stevequad

 

[BioniC187]

Oh wow, I think they look good Maybe you can experiment with the lighting also. Maybe PWM the lighting? perhaps at that speed, it will give some visual effect? Just a suggestion, I'm no photographer

I have a question, is the shutter speed at it's fastest setting when taking these shots?

 

[Stevequad]

actually the shutter speed is very slow its at about a quarter of a second.I have two or three flash units lighting the droplets with various gels on them for the different colors.the flash is set on manual at about 1-64th of power.everything is on manual, the flashes, the camera, and the lens focusing.
thanks for the kind comments I hope to get a lot better.

 

[atferrari]

Very good pictures. Congratulations!!