Re: 555 timer problem




randomname wrote:
I'm working on the "time fountain" project and have run into probably
the last of my problems. Here is the circuit (just strobing LEDs, and
a motor):

+6V
+------+ |
+6V>--+--[1N4001>]--+------|Vcc | [LED]
| |+ | | |K
| [1000µF] | OUT|----+
| | | |
GND>--|-------------+------|GND 5|--[.1uf]--|GND
| +------+
|
|
+--------------------------------------+
| |
| +----+----+
| | |
| [1N4001] [MOTOR]
| | |
| +------+ +----+----+
+6V>--+--[1N4001>]--+------|Vcc | |
|+ | | C
[1000µF] | OUT|---[R]--B
| | | E
GND>----------------+------|GND 5|--[.1uf]--|
+------+ GND

The top timer just controls strobing LEDs, and appears to be working
fine (though I have no real means to test it).

The bottom timer, however, gives me problems. I'm using a 1uf cap, 1K
for uptime, and 1K for downtime. (The configuration is such that one
resistor controls the cap charge, the other controls the discharge)

The motor is a tiny submersible 3vdc water pump. The problem is that
the frequency of the 555 timer will alternate. Ive hooked up a piezo
in parralel to the motor, so I can hear the frequency of the timer. (I
dont have an oscilloscope)

It will be high for a few seconds, then dip low for a few seconds, then
go back high. When this happens, it changes the RPMs of the motor
which changes the flow of water -- I need a constant flow of water. I
just need the motor to run steady at a certain rate, which it does, but
only for short bursts of time.

I need the 555 to stay as constant as possible... but for some reason
the 555 timer is giving me a hard time. Any suggestions? Thanks a
lot!

Maybe if you could post the exact circuit of the timer that controls
the motor, with all the parts and connections...
--
John

.



Relevant Pages

  • 555 timer problem
    ... The top timer just controls strobing LEDs, ... The bottom timer, however, gives me problems. ... The motor is a tiny submersible 3vdc water pump. ...
    (sci.electronics.basics)
  • Re: Clothes Dryer Taking Longer.....
    ... One pole and neutral run the motor and timer at 110V and both poles (w/o ... If the other breaker trips, ... kids overload the dryer. ...
    (alt.home.repair)
  • Re: pic micro programming
    ... revolution of the motor shaft. ... Any idea what the pulses you get, ... think over the basic idea of rpm and ways to measure it. ... Set up the counter to count external pulses and the timer for the time you ...
    (sci.electronics.repair)
  • Re: pic micro programming
    ... I as using a sensor which gives me 4 puls per ... revolution of the motor shaft. ... think over the basic idea of rpm and ways to measure it. ... Set up the counter to count external pulses and the timer for the time you ...
    (sci.electronics.repair)
  • Re: Garage door opener schematic
    ... the "up force" and "down force" controls are potentiometers used as rheostats to set the dc current fed into two pins of a control IC. ... Normally open contacts on those relays applies line voltage across one of two separate windings in the drive motor. ... The "other" motor winding gets a phase shifted voltage fed to it through a single capacitor connected between the "hot" ends of the two windings. ...
    (alt.home.repair)