Delay Circuit

I need to make a small 4-10 second (changeable) delay circuit that pulses a cell phone vibrational motor every 0.75 seconds. I'm using a 9 volt battery.

Could anyone please help me? Thanks!

Yes, your description is rather confusing. How does a 4 - 10 second delay circuit pulse a motor every .75 seconds?

NE556 + transistor.

If you do this circuit, I'll write the firmware.
POT to AIN0 (between +5 & GND).

full schematic

Excellent circuit with one little problem: it drives the motor at 9V, which will probably fry it. Typically, these cell phone vibrator motors only need around 1.5 volts.

Vibra (1.25V...) can be powered via LM317L

Yes! I have actually done this (except with an LM317 rather than an LM317L), it works great!

Combine this circuit with Eugene's and you might just have it.

Note: if the LM317L gets too hot (it will shut it self down until it cools off then turn back on, etc), then use an LM317 (and perhaps, a heatsink). Because the LM317L will have 9 volts on it's input, it will have to drop around 7.7 volts, so depending on the current draw of the motor, that could represent a significant power hit (estimated 1 to 5 watts). That's why this is an inefficient way of doing this. A buck converter would make this more efficient or even PWM using a 555 in place of the LM317 -- a 555 can source up to 200ma -- in fact I just thought of a cool way to do this -- next post).

OK, I haven't tried this but it should work -- the datasheet says that a reset happens at max 1 volt, so anything above that should be NOT reset.

Set the frequency to something like 30KHz and adjust the duty cycle on the 555 astable circuit until it just runs the motor at around 6.5V [the approx battery run down voltage]. This is a far more efficient way to do this, and this driver can be used with Colin's circuit, too [but instead of using a 3V supply, run the 74C14 directly from the battery].

This circuit will only work if the motor can be powered with 225ma or less. For higher currents use the 555 to drive a transistor (BiPolar or MOSFET -- which would then drive the motor).

NE555 possible to replace by IR2153D or IR21531D, to avoid additional transistor.

Nice!

next version:
voltage regulator for the Vibra, POT1 to ADC0, PWM out (OC0B) from MCU (if need PWM).

Suggest to LM317 calculator, to have the +1V5 as Vout:
R3 = K51
R4 = K10

Calculator for a few VoltRegs.

Its a shame really we have these rows? Its equally a shame that you cant work as a team Its also a great shame not to identify that the world is ever changing and with this you need to encourage people to learn new skills Its also a great shame that if you actually stopped and thought for a minute about all of these comments what you could do as a team and just how you could all contribute to making life easier , create a group effort , even make money , create jobs , better prospects and so on making life much nicer

However reading some of the information I find this quite amusing because if you sat back and looked through the comments Collin actually in one breath says its a waste of time learning about micros but Collin also goes on to answer a question on this forum regarding Hex notation with a subject regarding a similar micro controller in connection with addressing

Collin doesn’t realize no ones fault except maybe looking at yourselves sometimes that most equipment these days is all surface mount , bus architecture and networked either via RF as in a cell phone or via Ethernet , Optical fibre Collin also fails to understand the meaning of changing functionality of an integrated circuit on the fly hence because he has written one or two books which are good excellent stuff Collin , however technology is moving faster and faster and so this type of technology is out of date and not commensurate with modern demands recent article in Elektor electronics with the Chinese who have now developed a 1024 RGB led module complete with driver for operation via 3 wire bus

Whilst reading through this I can see very clearly what the problem is that the whole world is facing mass redundancies , insufficient training but also a very stubborn reluctance to learn new technologies which I hate to say works against you Hence the reason why so many companies businesses are faili8ng expecting everyone to pick up the peaces , the normal attitude of I don’t have to do this and I don’t have to learn this and therefore I wont not really helping anyone at all except hinder those who might just want to learn “Very negative if you ask me “ Also doesn’t really help Industry and creates a massive employment problem in the process rendering a nation of unemployables rather than a healthy steady economy

Just some observations

Although Collin suggests that that a pic micro circuit uses three less components What Collin doesn’t realize is that on a 5000 units as a whole entity this is quite a significant amount of money and can be the difference between making a market leader keeping a factory open and ensuring that staff remain employed plus of course are kept up to date with a reusable component

If Collin were to just listen sometimes instead of being so frustratingly obstinate we would have such a better atmosphere be able to work together each one listening and applying possibly Collins older technology which doesn’t change in theory and apply this to Modern technology

Once upon a time I had an engineer working for me a design engineer He was good at design he was from a computer science environment He also had some very good ideas both practical and theoretical A bit fo s strange character at time and pretty bloody useless when it cam to servicing what was then modern TV

However I also learnt quite a bit form this person who was younger than me just as I have form one or two other people Younger than me and that it is It pays to listen sometimes because looking back I whished Id kept him on he was that clever but being I suppose a little annoyed at the time with something he did which cost me an awful lot of money I failed to realize because of my own anger that he was extremely clever although strange and somewhat different .

These days I watch and listen and sometimes I argue as does everyone however I always try to look at what people are doing and ask questions and I tend to look at the older environment and seriously question their ability to provide decent incentives plus encourage people to learn and adopt a far wider broader outlook instead of wearing blinkers as many horses do

Nay though I may not be the cleverest individual in life My comprehension of Life is actually very broad indeed as to have my lessons been in life

I do hope Collin that you will start to see some sense in what people are saying here you do really need to listen and learn from these mistakes


I hope you will read this and think a bit more than you do sometimes all of you

Have a good evening who knows you might just all come up with a joint project that might make the difference between being trapped in poverty or being able to change the world

Good luck and totsiens

In case a uController solution isn't completely off the table, I just discovered the DigiSpark with DigiStump shields. I haven't tried it, so I can't vouch for ease of use, but it would be a cheap experiment. There is no need for a programmer because they plug into a USB port. It comes with an IDE (the thing that you write the code in and send it to the DigiSpark) that runs on your Windows/Mac OS/Linux PC. You write the program using the Arduino style programming language (looks a lot like C), and then load it onto the DigiSpark.

Two possible hitches:
* Might be hard to install the IDE -- not strait forward for a non-techie person
* The programming language might have a bit of a learning curve.

But, the parts are cheap:
* http://www.mcmelectronics.com/product/28-17748 [the DigiSpark]
* http://www.mcmelectronics.com/product/28-17754 [a MOSFET DigiStump shield that could be used to drive the motor]
* http://www.mcmelectronics.com/product/28-17750 [a protoboard shield for rolling your own driver]

Check out the DigiSpark WIKI for more info:

* http://digistump.com/wiki/digispark

And, one argument for using a uController over Colin's discrete analog solution is tighter timing. Especially with those 10uF caps (Colin made no mention of this, but if you just use the run of the mill aluminum electrolytic, they will likely have a tolerance of something like -10%, +75% which means the value of that 10uF capacitor can range from 9uF to 17.5uF -- not conducive to precise timing or even ballpark timing. So, if that is an issue, then be sure to purchase a capacitor with a tolerance value in line with your need (consider tantalum or even ceramic [X7R]):

* http://www.digikey.com/product-detail/en/199D106X9016C6B1E3/718-1199-2-ND/1559838
* http://www.digikey.com/product-search/en?x=0&y=0&lang=en&site=us&KeyWords;=+ +FK16X7R1C106K

Also, Aluminum Electrolytics are prone to drying out (I avoid them as much as I can).

With a uController you can do a lot better with timing stability and probably for less cost -- since you have to buy all those discrete components and pay for more PCB real estate (which, admittedly, probably isn't an issue in your case--only a concern for a _design engineer_).

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