555 and 4017 problem

[Lighty]

Hi All

Have a little problem with a 555 & 4017 setup.

The 555 is set to pulse HIGH for 150sec and LOW for 150sec, I'm using the "Enable" pin on the 4017, but what I've noticed is.

When the ENABLE changes to low while the CLOCK is still HIGH, the 4017 counts, how can I stop this?

Ideally I would need to have the 555 to pulse HIGH for 1 sec and LOW for 299 Sec, but don't think this can be done.

Could I put a trigger to only allow a 1 sec pulse from the 150 sec HIGH?

Thanks

 

[ericgibbs]

Hi All

Have a little problem with a 555 & 4017 setup.

The 555 is set to pulse HIGH for 150sec and LOW for 150sec, I'm using the "Enable" pin on the 4017, but what I've noticed is.

When the ENABLE changes to low while the CLOCK is still HIGH, the 4017 counts, how can I stop this?

Ideally I would need to have the 555 to pulse HIGH for 1 sec and LOW for 299 Sec, but don't think this can be done.

Could I put a trigger to only allow a 1 sec pulse from the 150 sec HIGH?

Thanks

hi,
To change the on/off ratio, connect a signal diode and resistor in series and connect these two components across one of the timing resistors.
This image shows the method.[ dont use these component values]

 

[Mikebits]

Why not just tie clock enable to ground?

 

[Lighty]

Thanks Eric, I'll give it a bash.

 

[Lighty]

Not with you?, I'm needing to use it.

 

[Mikebits]

You could go the synchronous route and resync your clock Enable signal to the falling edge of your 555 clock. This would guarantee that clock enable is low on the rising edge of 555 clock. See attached diagram.

 

[Lighty]

Thanks Mikebits, but to be honest, not not sure how your circuit would work.

But, here's my setup, its a battery charger that switched the charging source from 1 battery to the next, once full or starts to overheat.

The 4017 will output on 1 this will drive a transistor to power an external circuit to allow the charge to be supplied to that battery, The outputs from the voltage and temp monitoring circuits remain HIGH whilst the Voltage and Temp is below set thresholds, this along with a feed from the 4017 output is fed into the 4073 AND gate. Therefore the ouptut from the 4073 to the 4017 ENABLE pin will remain HIGH when the battery still needs charging and hasn't over heated. The feed from the 4017 output directly into the 4073 is to only allow that perticular charging channel to hold the sequance/transfer, otherwise if another battery was full and within temp it too would hold the circuit from transfering onto the next channel.

Now you are probably asking why is there a problem if the if the 4017 clocks before the NEXT clock, if a battery is just below the threshold, it may only charge for say 10 secs before triggering the 4017 to step to the next channel, I want the timing of the 555 to also be the minimun time that the battery should be charged, even if full.

Hope this all makes sence?

 

[Mikebits]

Well, your circuit seems a bit odd, and I will have to stare at a bit. Hard to read with everything sideways. As your diagram is drawn the diode or gate D1,D4 will not work right. It needs a pulldown resistor to ground on the cathodes. See image.

**broken link removed**
I am somewhat busy today as I am preparing for a 2 day rock collecting trip in Arizona. I will be out for the next few days, but I am sure Eric or someone else will be around to assist you. If not I will be glad to help when I return.

 

[Lighty]

Sorry Mike, my ciruits does have that pulldown resistor, just forgot to issulatate it.

Enjoy your trip.

 

[ericgibbs]

Sorry Mike, my ciruits does have that pulldown resistor, just forgot to issulatate it.

Enjoy your trip.

him
I know that you want a pulse from the 555 that is 1sec high and a 299sec low, thats easy to do.

But what is the purpose of the 4017 and what are you trying to do with the project.????

 

[Lighty]

Basic discription on post 7,

but to sum it up, its a battery charger that will be use to controll the output of an alternator to different batteries.

There will be 5 seperate batteries, when power up it will start in BATT1 until fully charged or starts to overheat, The circuit will drive a high current relay between each battery and the alternator. once the battery is charged it will use the 4017 to "count/move" to the next battery, BATT2, where the process repeats ifself.

The reason to use the "enable" function is to hold the 4017 untill the battery is charged or overheats.

The reason I want a 300sec/5 min timer is to ensure there is a minimum time the alternator is connected to the battery, even if full.

Another problem I might face is to general the "maximun" time that a battery is charged, so if a battery is damaged and not taking a charge, the "controller" doesn't just stay on it continueously.

Hope this give you a good idea?

 

[ericgibbs]

hi,
Thanks for the summary.
I was wondering why you have 4017/Q2 as RESET, I guess in the 5 battery version the RESET will be further down the 4017.
How are you sensing the charge state and temperature of each battery.?

 

[Lighty]

Yes, thats right, as more batteries are added RESET would be moved acordingly.

Battery voltage will be monitored with the circuit you have helped me with on anouther thread, https://www.electro-tech-online.com/threads/hysteresis-problem.107618/

and temperature with a 10K NTC on a similar type circuit.

 

[ericgibbs]

Yes, thats right, as more batteries are added RESET would be moved acordingly.

Battery voltage will be monitored with the circuit you have helped me with on anouther thread, https://www.electro-tech-online.com/threads/hysteresis-problem.107618/

and temperature with a 10K NTC on a similar type circuit.

ok,
So I will assume that when a battery is fully charged the voltage sensing circuit will give a High logic level, also if over temperature the Temp signal will go to a logic High.???
Will there be shared voltage signal, [one logic line] or will each battery have its own Vsense and logic level output.?
I assume that each battery will have its own temperature sensor and logic level output.?

EDIT:
Here is the 555 299/1sec pulse generator, use a CMOS version of the 555

 

[Lighty]

Thanks Eric.

Here a schem of the circuit.

The reason I've gone with the current opto setup, is incase a "monitor" module is not connected to the battery, it wouldn't hold the Enable high.

Do you understand what I'm trying to achieve, I'm taking it step by step to solving each problem as it comes...... probably not hthe best.

Other problems I know I'll have:

1. If the alternator voltage exceeds 14V ( in the event a battery has been disconnected, or fault with the high currrent relay) it must trigger the 4017 to step to the next battery, perventing the alternator running open circuit.

2. The maximum charge time, IE : say after 1 hour it must step to the next battery (as battery might be faulty)

 

[ericgibbs]

hi,
Looking at the circuit diagram, the logic isn't going to work the way you expect.

If you forget the actual variables that you are measuring and think in logic states it will be easier.

EDIT:
I know you are not using a PIC, but this project is ideal for a PIC/program.
To monitor all the states you are considering.
1. disconnected battery
2. battery under volts [ needs charging]
3. battery overheating
4. battery charging, but fails to rise to top Vset limit
5. 300 secs settling time between battery selection
6 and you are doing this for 5 individual batteries.

 

[Lighty]

Mmmm, am I missing something here?

If the battery is disconnected, or the battery is full, the LED on the 4n35 will be off (opto connected to + rail and sinking into the Opamp?), therefore the making the input into the Inverting buffer HIGH (due to pull up resistors), the output of the inverting buffer will be LOW, and along with the AND 4073 IC will make the ENABLE pin on the 4017 LOW, allowing it to step.

Is this not correct?

And if the battery is connected and is flat, the LED on the opto will turn ON, and basicaly ending up with the ENABLE pin HIGH (provided its not overheating and it active on that channel, feed from the feed from the outout of the 4017 into the 4073.

Yes, I do agree, this is a perfect PIC project, sadly I don't have the knowledge to even try attempt it....

EDIT:
I know you are not using a PIC, but this project is ideal for a PIC/program.
To monitor all the states you are considering.
1. disconnected battery
2. battery under volts [ needs charging]
3. battery overheating
4. battery charging, but fails to rise to top Vset limit
5. 300 secs settling time between battery selection
6 and you are doing this for 5 individual batteries.

Yip, that all the states.

 

[Lighty]

I'm confused, what did I miss? am I wrong?

 

[ericgibbs]

I'm confused, what did I miss? am I wrong?

hi,
My concern is that the design drawing is showing only one of the five control circuits, I think as the number of control circuits increases the logic is going to get very 'messy'
I will have a re-look over your logic to make sure.

This part also needs to be worked out

2. The maximum charge time, IE : say after 1 hour it must step to the next battery (as battery might be faulty)

The reason I want a 300sec/5 min timer is to ensure there is a minimum time the alternator is connected to the battery, even if full.

If I read this correctly, these two conditions, as you have only one battery voltage test line to each battery, means even with a fully charged or open circuit battery line, the alternator will run open circuit at this point for 300secs.??

1. If the alternator voltage exceeds 14V ( in the event a battery has been disconnected, or fault with the high currrent relay) it must trigger the 4017 to step to the next battery, perventing the alternator running open circuit.

It must appear that I am being negative in my posts, but I dont want to mislead you with your project.
I would advise you to draw out the complete design showing all 5 control circuits with any additional battery sensing.
Also consider the design requires some form of fail safe features.

 

[Lighty]

Thanks Eric, I do understand where you coming from, I'll try draw out the complete design tonight.

Thanks again.