Newbie: Solenoid timer circuit

[CurlyThom]

Hello,

I am fairly new to electronics and a first time poster so please be kind. I wish to create a circuit which sets off a row of solenoids one after the other. I have made an LED 555 timer circuit before but I understand that the voltages will be way too low for the solenoids or too high for the ICs.

Here is a circuit that I think is suitable:

I'm now going to make some crass assumptions on how I can modify it:

1. Change the LEDs to Solenoids
2. Have a high rail voltage so the solenoids work (this will also need to be varied to begin with so that the action of the solenoids is the correct stroke and strength)
3. Insert transistors between the solenoids and the 4017 IC and connect these to the higher rail voltage.
4. Insert a voltage drop resistor before 555 IC to protect both ICs

edit: these are the solenoids I have in question http://www.richmeg.com.tw/open_frame_solenoid_21_rgo1040l.html

Does what I've written make sense or am I grossly over simplifying things? Or is there a better / esier way to get what I want?

Many thanks

Thom

 

[Minder]

Use a ULN2803 UDN2981 or any of the similar darlington drivers.
M.

 

[Arouse1973]

Be kind because your new, no chance. As M said you need a driver for the solenoids.

 

[ver chan]

hello, your project is very similar to mine, ive use 1 pc In4001 diode, 1 pc, 100 ohms resistor, and connected it in between IC 4017 output pin and base pin of 2n3904 NPN transistor, the transistor will switch the solenoid of your relay, and the IC 4017 will switch the base pin of transistor, please send me a message if you made it.

 

[ver chan]

that circuit can actually drives 220 voltsAC lamp, just a little bit of modification is what you need

 

[Colin Mitchell]

You just need a power transistor connected as an emitter-follower for each output.

 

[CurlyThom]

Hey,
Thanks for all the replies. I see how a Darlington would make sense as you then have a common collector (is this right?).

I made a hash guess as to how I could do this as I don't like going on forums and just asking "how do I do this?" as it seems a bit lazy and rude. I will draw another circuit and upload for more feedback.

Thom

 

[Minder]

On the ULN Darlington packages the emitters are all common, collector output, they also have a BEMF diode included.
M.

 

[CurlyThom]

Okay. So here is my revised circuit. I am aiming to have the timer frequency at about 1.5Hz with a bit of fine tuning with the pot. Does this look sensible? I tried building the circuit using a Croc Clips demo but the 555 was blowing up under open circuit! so I gave up on that one.

edit: pin 1 on 555 is meant to be connected to 0v. woops!

Feedback is greatly appreciated.

Thom

 

[CurlyThom]

Also not entirely sure what the 47k resistor is doing as copied it from the last circuit but it's now shorted out...

 

[Minder]

The solenoids require to go to +24v Supply also pin 10 goes to 24v+, pin 9 goes to common.
M.
.

 

[ver chan]

i remember! you can also use opto coupler and triac,,, ic 4017 will drive and switch the opto coupler then it will drives the triac, then the triac can switch even the 220 volts ac load even without the use of relay

 

[CurlyThom]

Thanks Minder,
So do you mean like this?

 

[Minder]

Yes that appears to be OK now for the ULN2803..
M.

 

[CurlyThom]

Awesome, thanks Minder. Does the rest of the circuit look acceptable do you think?

 

[CurlyThom]

Hello Again,

Okay I have now built the circuit but I have run into some complications and need some troubleshooting advice if that's okay...
I have double checked the connections and continuity and all seems fine but the circuit is not operating as expected. I get one of the following when turning on the circuit:

• No response - circuit seems dead
• One solenoid activates but does not release - it stays down,

If I toggle the on off switch then it can change the solenoid that activates but in a seemingly random order. I have changed around the values of the capacitors and resistance but this has no effect. I have put a multimeter accross the outputs of the ULN2805 and the continuity beeper makes a kind of crackly scratchy noise rather than a beep and measures about 70 Ohms. Do I need to include a set of diodes with my solenoids?

It seems to me that the circuit is not counting forward, it is just closing the switch for one solenoid and keeping it there. I have tried moving the 4017 reset pin to pin 11 (8th output) on the ULN2805 but this has not changed anything.

Any help much appreciated as am at a bit of a loss....

Thanks