How do I supply two different adjustable voltages to a device with an adjustable timed interval between them with a single button press?
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M$2 Answers
But on to your question.
This should do it. You can adjust the inter voltage delay with the pot. Here's the source.
//##############################################
//# Camera Focus Cycle Controller
//# 07/02/2010
//# dainichi
//##############################################
#define LOWPOWER 9
#define HIGHPOWER 8
#define START 10
#define DELAY 0
void setup()
{
//set the start button pin to input mode
pinMode(START,INPUT);
//The arduino has built in pull up resistors on
//inputs this command turns them on.
digitalWrite(START,HIGH);
//make sure the outputs are in a known state
digitalWrite(LOWPOWER,LOW);
digitalWrite(HIGHPOWER,LOW);
}
void loop()
{
//define local variables
int local_delay;
//just a little switch debouncing
//
while(!digitalRead(START));
delay(10);
while(digitalRead(START));
//
//read the setting of the pot
local_delay = analogRead(DELAY);
//turn on the solenoid to low power
digitalWrite(LOWPOWER,HIGH);
//delay up to 1.024s (add a multiplier as neccesary)
delay(local_delay);
/*if you want to work on the order of microseconds */
/*instead of milliseconds, comment out the above line*/
/*and uncomment the following line */
//delayMicroseconds(local_delay);
//turn on the high power
digitalWrite(HIGHPOWER,HIGH);
//delay for a short time to allow the camera to
//detect the button press
delay(100);
//turn off the solenoid.
digitalWrite(LOWPOWER,LOW);
digitalWrite(HIGHPOWER,LOW);
}
I will post another solution as a comment below, in a bit.
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M$A time delay relay switches after an adjustable time delay. There is usually a knob on the top to adjust the delay duration.
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M$
I had looked at time delay relays before I posted but couldn't find any for less than
$75. I will definitely have to look more into this. As I said I don't have much experience with this kind of thing so any more information you could offer would be great.
Here is a simple circuit with adjustable low voltage and a time delay relay. A small heatsink may be needed on the transistor.
Here's a simple schematic for a time delay. K3 is a simple DPST relay for power control. K1 is a 24v time delay relay. 
I was planning on this being a universal mount so that any camera can be used. If I have to adjust the two input voltages for a different camera, will it affect this circuit? I've never used an arduino before but I think it's something we could figure out if that's the easiest and cheapest solution.
I was planning on this being a universal mount so that any camera can be used. If I have to adjust the two input voltages for a different camera, will it affect this circuit? I've never used an arduino before but I think it's something we could figure out if that's the easiest and cheapest solution.
Well, it's 0200h my time, If someone doesn't beat me to a solution using a 555/556 by the time i check in again tomorrow, i'll post my own version.
Cycle time will be however long it takes to take a picture. Maybe one second every five. Might be closer to half a second.
Just simple bottom-of-your-junkbox n-channel mosfets. And yes, K1 is just a standard 5v relay. Also, please note, I've altered the schematic to make use of the arduino's regulated 5v.
The new schematic will allow it to be used with any low voltage source 7.5v-24v (Although, 24 volts it pushing it heatwise, an upper end of 12-15v is more reasonable) and the high voltage can be anything the relay and Q2 can handle. Also, i added the flyback protection diode, that i forgot because i made the original at 3am
What are the transisters at Q1 and Q2? Also, is K1 just a simple relay?
Just in case you are wondering, the diode is important. It is to protect the lower voltage power supply from being driven the wrong way. The reason I have the schematics set up the way they are is to keep the solenoid constantly powered. If I had just designed it to switch between voltages, the split second when the relay contacts are not actually contacting anything may result in the solenoid letting go enough to reset the camera trigger.
The manner that I am using will allow the relay to just add pull to the solenoid.
As long as the lower voltage is greater than about 7.5 volts, and is powerful enough to activate the relay, then no, no problems. Or use a relay (K1) that is rated for 5v and tie it to the 5v pin of the arduino. (the arduino has an onboard regulator that can source about 150ma) Then, so long as the input to the arduino is greater than 5v plus regulator dropout (typicaly 1,2V) But to keep things reliable, we need to give the regulator some headroom too, so we'll set the minimum to about 7.5v.
If 24volts is going to be an issue with heat I may have to reconsider. We are talking about an intermmitent 24 volts. Maybe 20 percent duty cycle at the most for this application. Do you think that would be an issue? I may end up building both circuits. The time delay relay for simplicity and the arduino simply because I would love to get started working with these and it would be great excuse to do it. 12 volts will probably be the max on the low end so I am hoping that heat won't be an issue.
For short periods of time, the heat won't be an issue, but to mitigate it, just power the arduino from the lower voltage supply, or just remove the 24volt source between uses.
The voltage regulator dissipates the extra voltage as heat, so as long as power is applied it is dissipating heat. But you don't have to worry too much, the regulator is quite self-reliant. You really can't overheat them, if you try, they just shut down untill they cool off a bit.
For the record: 20% duty cycle is only half the story, you also need to specify the total cycle time.
Damn this system. Error 500 huh? Can't post a comment huh? SMDH
I was planning on this being a universal mount so that any camera can be used. If I have to adjust the two input voltages for a different camera, will it affect this circuit? I've never used an arduino before but I think it's something we could figure out if that's the easiest and cheapest solution.