555 timer problem

[Puckdropper]

Today I purchased a wall transformer from the dollar store (liars -- it
was $3.59) that has 1.5, 3 4.5, 6, 9, and 12 volts, and works with 110
or 220 volt inputs, and provides 500mA of current.

"Dollar store" is sometimes used by people to refer to Dollar General or
other such stores. They're not "Everything's a Dollar" or "Dollar Tree"
type stores.

So this replaces my 4 AA batteries, which would run weak after a couple
of hours. Strange thing is, when set to 6v it really makes my set-up
go crazy. The pump pumps way more liquid, and the strobe lights just
go crazy.. they flash brightly and irradically.

So I switched it to 3v and everything is fine. Pump runs very stable,
and the LEDs are steady and bright. It's been running for over an hour
completely stable (except for the normal hiccups and jitter caused by
my crappy pump). The wall transformer is just warm (about 115 F), so I
figure it's happy.

Take a close look at the battery connections. Does it go from + to - to
+ to - to + to - to + to -? Your 6V of batteries, for some reason, may
have been wired in parallel for 3V. (I.E., they know it's a battery hog
but sold it anyway.)

*snip*

-sam

Puckdropper

 

[John Popelish]

Today I purchased a wall transformer from the dollar store (liars -- it
was $3.59) that has 1.5, 3 4.5, 6, 9, and 12 volts, and works with 110
or 220 volt inputs, and provides 500mA of current.

So this replaces my 4 AA batteries, which would run weak after a couple
of hours. Strange thing is, when set to 6v it really makes my set-up
go crazy. The pump pumps way more liquid, and the strobe lights just
go crazy.. they flash brightly and irradically.

So I switched it to 3v and everything is fine. Pump runs very stable,
and the LEDs are steady and bright. It's been running for over an hour
completely stable (except for the normal hiccups and jitter caused by
my crappy pump). The wall transformer is just warm (about 115 F), so I
figure it's happy.

I wonder why I need to set it to 3v. If i switch it to 220v mode, I
need to crank it up to 12v for it to run about the same. If anyone can
explain this I'm all ears.

Oh well, it works!

I suspect your adapter is unregulated, and the switch just changes
transformer taps. The rated voltages only occur if you load the
adapter to its full current rating, and even then, there is some
tolerance and line voltage effects. If you under load it, relative to
its current rating, its output voltage will rise, perhaps rather
dramatically. Get a $10 (or less) multimeter from Walmart or Harbor
Freight Tools and measure the output voltage under your load.

 

[Homer J Simpson]

Today I purchased a wall transformer from the dollar store (liars -- it
was $3.59)

That's a "Dollar and More" store. No true dollar store sells these and you
got a good deal.

 

[ehsjr]

Today I purchased a wall transformer from the dollar store (liars -- it
was $3.59) that has 1.5, 3 4.5, 6, 9, and 12 volts, and works with 110
or 220 volt inputs, and provides 500mA of current.

So this replaces my 4 AA batteries, which would run weak after a couple
of hours. Strange thing is, when set to 6v it really makes my set-up
go crazy. The pump pumps way more liquid, and the strobe lights just
go crazy.. they flash brightly and irradically.

So I switched it to 3v and everything is fine. Pump runs very stable,
and the LEDs are steady and bright. It's been running for over an hour
completely stable (except for the normal hiccups and jitter caused by
my crappy pump). The wall transformer is just warm (about 115 F), so I
figure it's happy.

I wonder why I need to set it to 3v. If i switch it to 220v mode, I
need to crank it up to 12v for it to run about the same. If anyone can
explain this I'm all ears.

Oh well, it works!

-sam

See the post from John Popelish. Then add this circuit:

-----
+9 ---+----Vin|LM317|Vout---+----+---> +6
| ----- | |+
[C1] Adj [R1] [C2]
| | | |
| +----------+ |
| | |
| [R2] |
| | |
Gnd ----+----------+---------------+---> Gnd

C1 = .1uF, C2 = 10uF 25V
R1 = 240, R2 = 910

Mount the LM317 on a small heat sink.

The circuit regulates the 9V (nominal) coming
from your adapter to provide a steady 5.99 volts.
The adapter will put out more than 9 volts with no
load. You could set the adapter to 12 volts,
but that would be of no benefit, and would heat
up the LM317 more that it needs to be.

Ed

 

[Jamie]

Today I purchased a wall transformer from the dollar store (liars -- it
was $3.59) that has 1.5, 3 4.5, 6, 9, and 12 volts, and works with 110
or 220 volt inputs, and provides 500mA of current.

So this replaces my 4 AA batteries, which would run weak after a couple
of hours. Strange thing is, when set to 6v it really makes my set-up
go crazy. The pump pumps way more liquid, and the strobe lights just
go crazy.. they flash brightly and irradically.

So I switched it to 3v and everything is fine. Pump runs very stable,
and the LEDs are steady and bright. It's been running for over an hour
completely stable (except for the normal hiccups and jitter caused by
my crappy pump). The wall transformer is just warm (about 115 F), so I
figure it's happy.

I wonder why I need to set it to 3v. If i switch it to 220v mode, I
need to crank it up to 12v for it to run about the same. If anyone can
explain this I'm all ears.

Oh well, it works!

-sam

you did say 110/220 ? i don't know what country your from but are you
sure you aren't really using 220 on the input and getting twice of what
you think on the output?
it seems very strange that a unit like that would be rated to use
either voltage with out a line switch option?

 

[feebo]

Today I purchased a wall transformer from the dollar store (liars -- it
was $3.59) that has 1.5, 3 4.5, 6, 9, and 12 volts, and works with 110
or 220 volt inputs, and provides 500mA of current.

So this replaces my 4 AA batteries, which would run weak after a couple
of hours. Strange thing is, when set to 6v it really makes my set-up
go crazy. The pump pumps way more liquid, and the strobe lights just
go crazy.. they flash brightly and irradically.

So I switched it to 3v and everything is fine. Pump runs very stable,
and the LEDs are steady and bright. It's been running for over an hour
completely stable (except for the normal hiccups and jitter caused by
my crappy pump). The wall transformer is just warm (about 115 F), so I
figure it's happy.

I wonder why I need to set it to 3v. If i switch it to 220v mode, I
need to crank it up to 12v for it to run about the same. If anyone can
explain this I'm all ears.

Oh well, it works!

-sam

sounds like it's unregulated (price would suggest this too)

unregulated supplies give (say) a nominal 6 volts on load, but when
not loaded or lightly, the voltage will drift high. I have once such
supply that gives 17.5v on no load set to 12v! If this is the case
with your wallwart, then you may have been giving your thingy way more
that it was expecting (hence the higher volume pumped - the pump was
running faster)

Either:
A. put a regulator circuit in the output so that 6 volts really is 6
volts.
or
B. Leave it on 3v if all seems well