I replaced the cap until I found one that makes the voltage drop in ~60 sec. So I replaced the LED and resistor with a 470Ω resistor and measure the voltage over time. At 30 ma the equivalent resistance should be ~ 483Ω. So I had a plan based on the video in post #4. Do not feed the 12V into Vin: you're almost guaranteed to eventually kill the arduino's on board regulator. I suggest a reverse-protection diode on the 12V input, followed by a large cap (around 100uF or so), into a 7805 regulator and feed that to the arduino 5V input. You will also need to clean that power supply up. ![]() You'll need to power the arduino from the unswitched 12V acc line of course. Simple code to read input, activate relay and as long as switched 12V doesn't come back on, keep relay closed until 60 second timeout. Just search the forums or buy a relay board.Īs far as how to trigger the behavior, monitor the switched 12V ignition line - ideally use an optocoupler or a resistor and zener diode to reduce the 12V to something safe for arduino, then turn the relay on when it drops out and hold the relay closed for 60 seconds. There are thousands of examples of turning a relay on or off with an arduino. ![]() For example, they may be used in conjunction with one another to make lamps flash on and off.What part do you need help with? The relay activation or the initial trigger? Some repeat cycle timers start the off-timer first, while others begin with the on-timer. These cycles will continually repeat as long as the voltage is applied to the time delay relay. Repeat cycle timers have two controls so that cycles are independently adjustable. ![]() The timer is reset by removing the voltage and then reapplying it. The on-cycle and off-cycle times are the same lengths. When an input voltage is applied to a flasher, the contacts energize and de-energize after one another. A range of general purpose and demanding industrial and commercial applications,.Interval-on time delay relays may be used for: The input voltage has to be removed so that the time delay relay can be reset. The output is de-energized once the delay period is over. Operate electrical devices and motors for a specified time, such as coin-operated dryers in commercial laundries.Īlso referred to as one-shot timers, the output for interval-on timers is already energized and the time delay starts when the input voltage is applied.Air-conditioning systems to hold the blower motor in operation for a specific time period after the thermostat has turned the cooling compressor off.If the trigger is applied during the delay, it will reset. An output is de-energized at the end of the time delay period. An output is energized by applying the trigger, which must be removed for the time delay to start. Off-delay timers are ready to accept the trigger when the input voltage is applied. This avoids excessive surge current in the power line. Stagger starting times for multiple compressors or motors that are activated by the main switch.Blower motors to delay the operation for a specific time period after a gas, electric, or oil heater has been turned on.Input voltage has to be removed to de-energize the output and reset the time delay relay.Īlso referred to as delay-on-operate timers, they are often used for: The output is energized at the end of the delay. Normally open, on-delay timers start timing when the input voltage (power) is applied. Other types include interval-on-operate, flasher, and repeat cycle timers. On- and off-delay relay timers represent the most widely used time delay relays. The type of time delay relay used depends on the system setup. The trigger signal can be either a dry-contact control switch, such as a float switch, limit switch, or push button or with voltage. Generally, a time delay relay is triggered either by opening or closing a circuit or by providing an input current. A time delay relay provides a scheduled window to clear noxious gases from the chamber. Ex: a time delay relay can ensure that the items move from one conveyor to another to prevent a pileup.Īs a safety application example, furnaces require ventilation to get rid of fumes and avoid the possibility of explosions. Time delay relays can control loads or production processes in many ways. Time delay relays can also make sure that the different parts of a machine start separately at predetermined times, such as: Triggered in various ways, time delay relays minimize the energy used to start large industrial machinery or can switch on and off light switches. Timing relays have a built-in time-delay function. Time delay relays are parts that activate a multitude of appliances, machinery, and equipment. NOTE: Technical data sheets available for reference purposes only. ![]()
0 Comments
Leave a Reply. |