Does the relay switch of your monostable circuit triggered when time starts and at the end?

See post #12. yes it does. the only thing that can go wrong is the interconnection to your timer circuit. there should be no transients on the CMOS chip input, no long wires etc.

Also, I forgot, all unused inputs should be tied to GND.

 

What do you mean by this?

 

Gtg i need to eat my lunch. LOL! Its almost 2 o'clock in the afternoon here.:^_^

 

Mr. Praondevou, where did you get your Tektronix? Would you mind giving me an idea how much it will cost me if i buy that thing?

 

I don't have a tektronix (I wish I had , in my other company they had a 4 channel digital storage from tektronix with ISOLATED inputs, really helpful this one). What I posted is a MultiSim simulation. You find the oscilloscope at the right hand tool bar.

If you mean you wish to buy real oscilloscope, I wouldn't recommend a Tektronix digital storage for a beginner or someone who occasionally does some electronics projects, they are EXPENSIVE. There are cheaper options.

 

Hi, i still haven't used the schematic that you gave the other day to me. I can't find the component you used as U3A.

Would you mind giving the specific component types, model and values like Volts, watts and its function.

Thanks

 

Hi, i still haven't used the schematic that you gave the other day to me. I can't find the component you used as U3A.

Would you mind giving the specific component types, model and values like Volts, watts and its function.

Well I don't know what your location is, but there shouldn't be a problem in finding a 40106 CMOS IC. The exact specs of all the components in this circuit are not critical.

40106 - any, I chose this one because it has schmitt trigger inputs, I guess in your case almost any logic gate that has a inverter function can be used NAND, NOR, etc
555 - any
C2,C5 - Elco at least 20V
all other Cs - anything except ceramic maybe
resistors - any type / above 1/8W

 

Is the input source from the digital timer that you are telling is the supply coming out from the relay when i connect the common pin to 12vdc? if it is, how does it trigger again if the relay turn back to its normal position and no supply coming out from common pin (How does the monostable signal relay be triggered)?

 

Is the input source from the digital timer that you are telling is the supply coming out from the relay when i connect the common pin to 12vdc? if it is, how does it trigger again if the relay turn back to its normal position and no supply coming out from common pin (How does the monostable signal relay be triggered)?

I don't understand this question.

The output of the digital timer you bought will give out a rectangular signal, alternating between 0VDC and 12VDC in , right?


PLEASE READ THE FOLLOWING :

Normally the digital timer output signal is 0VDC. Someone puts a coin into the coin slot, this triggers the digital timer. So the output of the timer goes HIGH (12VDC).

This will trigger the 555 monostable and closes its output relay contacts for 2.4 sec.

The digital timer counts until 10min, then its output signal goes LOW, which triggers the monostable again which in turn closes again the output relay for 2.4 sec.

The NO contact from your digital timer relay you connect one side to +12VDC, the other side of the NO contact to a resistor of e.g. 47k, then the other side of the resistor to GND. The voltage over the resistor will alternate between 0VDC and 12VDC. This is the signal you feed to the 555 circuit.

You could also use the digital timer output signal that drives its relay coil. What's the voltage there ? 5V?

 

It seems i've found the IC (inverter) you used in your monostable diagram. The only components that i am looking now is the capacitors with nF values.

You told me any capacitors except ceramics, why?
What is the problem with that type of capacitor?

Yes its a regulated 5vdc coming out from the 7805 regulator. This voltage drives the large IC, LED display and the other transistors. The only 12v supply is in the section of two(2) relay switch with a protector diode. Normally, the current flowing in the pin 1 of the relay coils is 12v when a coin is not yet inserted. The pin one (1) will just turn to 0v in the anode section if a coin is triggered.

 

You told me any capacitors except ceramics, why?

Most common ceramic caps are quite senstive to temperature changes (some special types are not (can't remember the type right now)), so I wouldn't use them in timing applications.

 

What if i cannot find those values in mylar type what is the alternative type of capacitors will i use?

If there's an alternative circuit diagram act the same way like the monostable circuit that you've given to me. Please send me a copy.

Most of the electronic stores that i have visited gives me a ceramic type of capacitors, but I will try to find those mylar in the stores.

 

Actually, your circuit doesn't require very tight tolerances, so if there is no other way you can use ceramic too. I'd normally not use them for any application where it determines the time of anything.

But in your case the values are not critical, so even the ceramic should work.

 

Good day!

I've tried your monostable and it works perfectly. Thank you very much!

BTW, do you know who posted the charging control for mobile phone after two (2) hours? Hes said that the 220v supply connecting by mobile phone charger will automatically cut after reaching the said time. He also posted his circuit diagram in his thread.

I would like to try his circuit, but unfortunately i don't know what the thread title he posted it. I hope you can help me...

Thanks