Help - timing and switching circuit needed

Check this out, Google on what you don't understand, and ask again if you need help.

Good luck, Steve.

Chuck

Two Simple 24-Hour Timer Circuit Schematics

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Do you mean that solenoid 1 operates, then 12-48 hours later solenoid 2 operates, then 12-48 hours later solenoid 3 operates, etc?

Ed

Ok, a long duration sequencer.

What is the "single pulse" ??

Any microcontroller chip with a RTC (real time clock) chip and a relay driver chip can do this.

Are you looking at "building this yourself" by,

a) buying computer/logic boards and programming them yourself. b) building your computer/logic PCBs and soldering the chips down yourself then programming them. or c) buying a complete system that can control relays with a "single pulse"

How much of "build it" are you interested in doing ??

donald

Sorry, the description I gave was a bit wooly. The solenoid acts to open a small catch - all it needs is one pulse to make it pull. ie: No need for a permanent current to be applied. Hope that makes sense.

Was hoping to do a complete self build but if there is something ready made then why re0invent the wheel so to speak?

Was hpong that what I need would be some combination of a 555 chip and relay etc. Wasn't imagining anything like programming as that would probably be quite beyon my capabilities.

I could cope (just) with buying components and soldering them together :-(

There's a kit than can be set up to give you a pulse every ~22 hours (or less).

You would need to add two circuits: a 4017 counter to advance to the next solenoid when the kit provides a pulse, and a solenoid driver circuit that will provide a pulse to the solenoid. We need to know a couple of things. How long does the pulse to the solenoid have to be, at a minimum? How much current does the solenoid take? Can you build the two additional circuits without using a kit?

Ed

Thanks Ed. The solenoid I was looking to use can be seen at

Not suggesting you look it up - just wanted to state it in case you wanted to look. I have downloaded the technical data sheet but it doesn't seem to give the details so I have emailed the company and asked. I'll post back when I get a reply.

I understand what you have suggested (many thanks indeed) and it makes sense. Whilst I am probably OK with the solenoid driver circuit; the technical data sheet I downloaded gives me some examples and they seem straight forward. However, the 4017 counter - I wouldn't know where to start. Is it likely that a kit is available?

There is a kit CAT# AEC at Allelectronics

It is an LED chaser kit - you would need to modify it (simple - don't install the 555). As designed, a

555 runs as an astable. The output of the 555 clocks the 4017 counter - the output of the counter drives the LEDs. You would use the QK152 output to create the clock pulse that advances the 4017 counter. Connect teh QK152 output to pin 14 of the 4017. You would also need to modify the QK152 to reset itself when it reached the period you select so that it starts timing all over again. (Mod described below)

Here's how you could do it: In the QK152 when the 4020 counter reaches a value of 8, use that pulse to activate the solenoid driver. When the count reaches the value equal to your period, use that pulse to advance the 4017. The same pulse is used to reset the 4020 to 0 (connect the reset pin, pin 11, to the pin for the period you chose). The 4017 count is used to energize a relay or bias a transistor on so that when the solenoid driver pulse arrives ~ 8 seconds later, the correct solenoid is fired.

QK152 mod: you need to connect pin 4 of the 555 to pin 8 of the 555, and remove the connection from pin

4 of the 555 to the collector of Q1. The collector of Q1 needs to remain connected to R7 if you wish to use the transistor outputs for something. As mentioned above, you need to connect the period output pin to tyhe reset pin to set the 4020 to 0.

Ed

Aargh! There was an error in my reply. I have modified the reply, below, to correct the error. The good news is that it will simplify things, and save needing a solenoid driver.

There is a kit CAT# AEC at Allelectronics

It is an LED chaser kit - you would need to modify it (simple - don't install the 555). As designed, a 555 runs as an astable. The output of the 555 clocks the CD4017 counter - the output of the counter drives the LEDs. You would use the QK152 8192 output (4020 pin 3) to create the clock pulse that advances the 4017 counter. Connect the QK152 4020 pin 3 to pin 14 of the 4017 in the AEC kit.

Here's how you could do it: In the QK152 when the 4020 counter reaches a value of 8192, use that pulse to advance the 4017 in the AEC. The 4017 count is used to bias a transistor on so that when the solenoid driver relay pulse arrives ~ 8 miliseconds later, the correct solenoid is fired.

AEC mod: omit 555 and LEDs. Remove existing connection to 4017 pin 15 and connect count N+1 output pin to pin 15, where N is the number of solenoids. See the 4017 datasheet.

QK152 mod: you need to connect pin 4 of the 555 to pin 8 of the 555, and remove the connection from pin 4 of the 555 to the collector of Q1. The collector of Q1 needs to remain connected to R7. Use the QK152 relay contact to connect + to the solenoid. Partial schematic below.

QK152 Relay contact +24 -----o--- ^---o----+----+------+----+------+----+--}}---- | | | | | | [Sol1] [D1] [Sol2] [D2] [Sol3] [D3] | |a | |a | |a +----+ +----+ +----+ | | | /c | | 4017 pin 3 --[R]--| NPN | | \e | | | | | Gnd | | /c | 4017 pin 2 ---------[R]-------| NPN | \e | | | Gnd | /c 4017 pin 4 ---------[R]-------------------| NPN \e | Gnd

Note that it assumes 24V solenoids. The relay contacts in the QK152 can handle up to 10 amps. The transistors have to be chosen to handle the solenoid current and may need to be darlingtons or FETs. R should be at least 1K

Ed

Many thanks Ed, really appreciated. I will pull this together and have a go.

google for 555+monostable

and 555+relay

If you'd asked in s.e.b I'd have posted you a schematic.

Bye. Jasen