Watch Winding Project

I am new to the forum and to the field of electronics in general. As background, I did build my own PC though that is a different skill set.

My project is that I would like to run a 1.5 to 3VDC Hobby Motor to run for lets say 5 seconds every 15 minutes. I'm not too anxious to start with a whole microcontroller project. Can I do this using resistors or capacitators? This will need to run 24/7 so it can't run too hot or be a fire hazard or anything. Low cost is a priority.

I realize this question is general and if there is a resource that I can read without taking up too much time, I'd be glad to RTFM.

Thanks in advance.

Ken

Read up about the '555 timer'.

alec_t said:

Read up about the '555 timer'.

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Thanks alec. I looked in Wikipedia and on Youtube (see video laB2zNU5s_Y). The 555 timer IC has 8 prongs: 1=ground, 2=trigger, 3=output, 4=reset, 5=control voltage, 6=threshhold, 7=discharge, 8=positive supply. Which of these prongs specifies the delay between starting the motor and stopping it (phase 1)? Also, which of these prongs specifies the delay between stopping the motor and then starting it again (phase 2)? Also is there an on-line reference that gives me more information then the wikipedia article in easy-to-understand language for non-engineers?

~ Ken

For the full info, download the 555 datasheet (Google for it). If you configure the chip (the CMOS version) as an astable multivibrator you can choose resistor and capacitor values so that the chip output (pin 3) repeatedly cycles through 'Hi' and 'Lo' states, with the 'Hi' duration being 5 secs and the 'Lo' duration being 15 mins. The 'Hi' state is then used (probably with a power driver stage, depending on your motor current/voltage requirements) to switch on the motor.

If you check the 'Tools' section of this forum you will find a 555 Calculator for determining timing component values.

The 'Astable' section of the Wiki article gives details of how the various pins need to be connected for that timing mode.

Just a couple of questions and we can make you a schematic. What will your power supply be? Do you know the current of your motor?

could 555 could provide a long 'Lo' duration of 15 minutes

could 555 could provide a long 'Lo' duration of 15 minutes

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According to its spec the CMOS version (7555) should be able to, providing a low leakage cap is used. If that's tricky to source it might be better to use a 7555 to clock a counter.

You can do it with 4 transistors.

You can do it with 4 transistors.

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Would you care to explain how to the OP (who is new to the field of electronics)?