can i use a 12 volt battery on a 9 volt device ?

[hhgggff]

My friends dad is building a Tardis for his grandson.

We have rigged up the blue flashing light using a 12 volt car battery, we
now need to sort out the sounds.

I was thinking of using an old cars cassette tape, but I have an old 9 volt
portable cassette handy.

Will it burn down the TARDIS if I use that instead ?

tafankuverymuch

 

[ian field]

"hhgggff" <ohu@klg.con> wrote in message
newso16m.54775$OO7.27875@text.news.virginmedia.com...

My friends dad is building a Tardis for his grandson.

We have rigged up the blue flashing light using a 12 volt car battery, we
now need to sort out the sounds.

I was thinking of using an old cars cassette tape, but I have an old 9
volt portable cassette handy.

Will it burn down the TARDIS if I use that instead ?

tafankuverymuch

You can get simple to use regulator chips that drop the voltage down, you
only need a couple of components to make a working voltage regulator. Ask on
News:sci.electronics.basic - the folk on there are usually very helpful and
should explain all you need.

 

[richard]

On Sat, 11 Jul 2009 14:33:07 GMT, "hhgggff" <ohu@klg.con> wrote:

My friends dad is building a Tardis for his grandson.

We have rigged up the blue flashing light using a 12 volt car battery, we
now need to sort out the sounds.

I was thinking of using an old cars cassette tape, but I have an old 9 volt
portable cassette handy.

Will it burn down the TARDIS if I use that instead ?

tafankuverymuch

Go to your local radioshack and buy a 9v voltage regulator.
12 volts in 9 volts out. Get a 5 or 3 amp fuse so the player will only
draw the amps it needs.

 

[doS]

you can only jump a few more lightyears with 12 volt.

"hhgggff" <ohu@klg.con> wrote in message
newso16m.54775$OO7.27875@text.news.virginmedia.com...

My friends dad is building a Tardis for his grandson.

We have rigged up the blue flashing light using a 12 volt car battery, we
now need to sort out the sounds.

I was thinking of using an old cars cassette tape, but I have an old 9
volt portable cassette handy.

Will it burn down the TARDIS if I use that instead ?

tafankuverymuch

 

[Electronworks.co.uk]

"richard" <member@newsguy.com> wrote in message
news:bjah55tad51p1so48jsl3lusgvel80a4il@4ax.com...

On Sat, 11 Jul 2009 14:33:07 GMT, "hhgggff" <ohu@klg.con> wrote:

My friends dad is building a Tardis for his grandson.

We have rigged up the blue flashing light using a 12 volt car battery, we
now need to sort out the sounds.

I was thinking of using an old cars cassette tape, but I have an old 9
volt
portable cassette handy.

Will it burn down the TARDIS if I use that instead ?

tafankuverymuch


Go to your local radioshack and buy a 9v voltage regulator.
12 volts in 9 volts out. Get a 5 or 3 amp fuse so the player will only
draw the amps it needs.

Richard

You are implying the fuse will limit the current, which of course it will
not. OK the regulator may have some current limiting in it, but a fuse will
not be much good

--
Bill Naylor
www.electronworks.co.uk
Electronic Kits for Education and Fun

 

[ian field]

"chuckcar" <chuck@nil.car> wrote in message
news:Xns9C459893424AFchucknilcar@127.0.0.1...

"hhgggff" <ohu@klg.con> wrote in
newso16m.54775$OO7.27875@text.news.virginmedia.com:

My friends dad is building a Tardis for his grandson.

We have rigged up the blue flashing light using a 12 volt car battery,
we now need to sort out the sounds.

I was thinking of using an old cars cassette tape, but I have an old 9
volt portable cassette handy.

Will it burn down the TARDIS if I use that instead ?

The tape motor will run at the wrong speed for one. What you need is a
voltage regulator. A 7809 should do the trick. The 7800 series convert DC
voltages. Granted a transformer does it, but these handle *much* wider
voltage inputs and are tiny in comparison. A 7812 hooked to the +12v
connection with the other connection hooked to a 200 microfarad capacitor
should give you a rock solid +9v out. You'll need a piece of breadboard
about 1" square to mount these on.

You should read up on a subject you know little about before giving advice
to others.

Even in older cassette recorders the motors had centrifugal speed governors
and modern ones have an IC speed controller (otherwise they'd run slower and
slower as the battery was used).

Your mention of transformers is misleading, without a "chopper" circuit to
convert DC into AC a transformer will burn out.

The OP is best advised to ask people who are equipped to give accurate
advice, such as the folk on News:sci.electronics.basics .

 

[chuckcar]

"hhgggff" <ohu@klg.con> wrote in
newso16m.54775$OO7.27875@text.news.virginmedia.com:

My friends dad is building a Tardis for his grandson.

We have rigged up the blue flashing light using a 12 volt car battery,
we now need to sort out the sounds.

I was thinking of using an old cars cassette tape, but I have an old 9
volt portable cassette handy.

Will it burn down the TARDIS if I use that instead ?

The tape motor will run at the wrong speed for one. What you need is a

voltage regulator. A 7809 should do the trick. The 7800 series convert DC
voltages. Granted a transformer does it, but these handle *much* wider
voltage inputs and are tiny in comparison. A 7812 hooked to the +12v
connection with the other connection hooked to a 200 microfarad capacitor
should give you a rock solid +9v out. You'll need a piece of breadboard
about 1" square to mount these on.

http://en.wikipedia.org/wiki/78xx

--
(setq (chuck nil) car(chuck) )

 

[chuckcar]

"ian field" <gangprobing.alien@ntlworld.com> wrote in
news:VZ56m.172$Ae3.44@newsfe01.ams2:

"chuckcar" <chuck@nil.car> wrote in message
news:Xns9C459893424AFchucknilcar@127.0.0.1...
"hhgggff" <ohu@klg.con> wrote in
newso16m.54775$OO7.27875@text.news.virginmedia.com:

My friends dad is building a Tardis for his grandson.

We have rigged up the blue flashing light using a 12 volt car battery,
we now need to sort out the sounds.

I was thinking of using an old cars cassette tape, but I have an old 9
volt portable cassette handy.

Will it burn down the TARDIS if I use that instead ?

The tape motor will run at the wrong speed for one. What you need is a
voltage regulator. A 7809 should do the trick. The 7800 series convert
DC voltages. Granted a transformer does it, but these handle *much*
wider voltage inputs and are tiny in comparison. A 7812 hooked to the
+12v connection with the other connection hooked to a 200 microfarad
capacitor should give you a rock solid +9v out. You'll need a piece of
breadboard about 1" square to mount these on.


You should read up on a subject you know little about before giving
advice to others.

Considering the fact that my post is *far* more detailed than yours,

you're hardly a person to make such a judgement = along with your errors
detaied below.

Even in older cassette recorders the motors had centrifugal speed
governors and modern ones have an IC speed controller (otherwise they'd
run slower and slower as the battery was used).

And none of this would burn out with 1 1/3 times the voltage input?

dubious.

Your mention of transformers is misleading, without a "chopper" circuit
to convert DC into AC a transformer will burn out.

He's *using* a DC power source - a car battery. So a rectifier circuit or

an analogue is completely unncessary

The OP is best advised to ask people who are equipped to give accurate
advice, such as the folk on News:sci.electronics.basics .

One *minor* correction of my post however - that *should* have been a 7809

not a 7812. This I picked up immediately when I read your reply. A pretty basic
error you didn't even notice. a 7812 converts *to* 12v whereas a 7809 converts
to 5v. Hence their names.

--
(setq (chuck nil) car(chuck) )

 

[Any one]

chuckcar wrote on 11-Jul-09 12:17 :

"hhgggff" <ohu@klg.con> wrote in
newso16m.54775$OO7.27875@text.news.virginmedia.com:

My friends dad is building a Tardis for his grandson.

We have rigged up the blue flashing light using a 12 volt car battery,
we now need to sort out the sounds.

I was thinking of using an old cars cassette tape, but I have an old 9
volt portable cassette handy.

Will it burn down the TARDIS if I use that instead ?

The tape motor will run at the wrong speed for one. What you need is a
voltage regulator. A 7809 should do the trick. The 7800 series convert DC
voltages. Granted a transformer does it, but these handle *much* wider
voltage inputs and are tiny in comparison. A 7812 hooked to the +12v
connection with the other connection hooked to a 200 microfarad capacitor
should give you a rock solid +9v out. You'll need a piece of breadboard
about 1" square to mount these on.

http://en.wikipedia.org/wiki/78xx

AHAHAHAHAHAHAHAHAHA!!!!

....are you completely deranged, chucktard?

 

[John Fields]

On Sat, 11 Jul 2009 21:50:55 +0000 (UTC), chuckcar <chuck@nil.car>
wrote:

"ian field" <gangprobing.alien@ntlworld.com> wrote in
news:VZ56m.172$Ae3.44@newsfe01.ams2:


"chuckcar" <chuck@nil.car> wrote in message
news:Xns9C459893424AFchucknilcar@127.0.0.1...
"hhgggff" <ohu@klg.con> wrote in
newso16m.54775$OO7.27875@text.news.virginmedia.com:

My friends dad is building a Tardis for his grandson.

We have rigged up the blue flashing light using a 12 volt car battery,
we now need to sort out the sounds.

I was thinking of using an old cars cassette tape, but I have an old 9
volt portable cassette handy.

Will it burn down the TARDIS if I use that instead ?

The tape motor will run at the wrong speed for one. What you need is a
voltage regulator. A 7809 should do the trick. The 7800 series convert
DC voltages. Granted a transformer does it, but these handle *much*
wider voltage inputs and are tiny in comparison. A 7812 hooked to the
+12v connection with the other connection hooked to a 200 microfarad
capacitor should give you a rock solid +9v out. You'll need a piece of
breadboard about 1" square to mount these on.


You should read up on a subject you know little about before giving
advice to others.

Considering the fact that my post is *far* more detailed than yours,
you're hardly a person to make such a judgement = along with your errors
detaied below.

---
The fact that your post was more "detailed" than Ian's doesn't mean that
his was wrong.
---

Even in older cassette recorders the motors had centrifugal speed
governors and modern ones have an IC speed controller (otherwise they'd
run slower and slower as the battery was used).

And none of this would burn out with 1 1/3 times the voltage input?
dubious.

---
Just conjecture without knowing more about the cassette recorder.
---

Your mention of transformers is misleading, without a "chopper" circuit
to convert DC into AC a transformer will burn out.

He's *using* a DC power source - a car battery. So a rectifier circuit or
an analogue is completely unncessary

---
But, since his application runs on DC, your reference to a transformer
was misleading since a transformer takes an AC input and supplies an AC
output which must then be rectified, filtered, and possibly regulated
before it can be used by the DC input device.

If, by "transformer", you meant an AC to DC converter, then your
terminology was wrong.
---

The OP is best advised to ask people who are equipped to give accurate
advice, such as the folk on News:sci.electronics.basics .

One *minor* correction of my post however - that *should* have been a 7809
not a 7812. This I picked up immediately when I read your reply. A pretty basic
error you didn't even notice. a 7812 converts *to* 12v whereas a 7809 converts
to 5v. Hence their names.

---
???

A 7809 converts to 9V, not 5V.

In addition, not knowing the current requirements of the recorder, your
comment to build it on one square inch of breadboard (perfboard?) may
well be inconsistent with the heat-sinking required for the regulator.

And why the 200ľF capacitor?

Why not 10?

Why not 1000?

JF

 

[Zootal]

<snip>

A 7809 converts to 9V, not 5V.

In addition, not knowing the current requirements of the recorder, your
comment to build it on one square inch of breadboard (perfboard?) may
well be inconsistent with the heat-sinking required for the regulator.

And why the 200ľF capacitor?

Why not 10?

Why not 1000?

JF

Forget the regulator. Connect 4 diodes in series with the power supply and
that will get you into the ballpark. Just make sure the diodes can handle
the max current the thing will draw.

 

[John Fields]

On Sun, 12 Jul 2009 11:58:58 -0700, "Zootal"
<usenet@spam.zootal.nospam.com> wrote:

snip


A 7809 converts to 9V, not 5V.

In addition, not knowing the current requirements of the recorder, your
comment to build it on one square inch of breadboard (perfboard?) may
well be inconsistent with the heat-sinking required for the regulator.

And why the 200ľF capacitor?

Why not 10?

Why not 1000?

JF


Forget the regulator. Connect 4 diodes in series with the power supply and
that will get you into the ballpark.

---
But, (although it may not matter if the recorder's motor speed is
maintained constant by the recorder itself) the output voltage will fall
as the battery voltage does.

JF

 

[hhgggff]

I will look into a voltage regulator but will probably just get an old car
stereo as it's easier

tafankuverymuch

 

[mr deo]

"hhgggff" <ohu@klg.con> wrote in message
newso16m.54775$OO7.27875@text.news.virginmedia.com...

My friends dad is building a Tardis for his grandson.

We have rigged up the blue flashing light using a 12 volt car battery, we
now need to sort out the sounds.

I was thinking of using an old cars cassette tape, but I have an old 9
volt
portable cassette handy.

Will it burn down the TARDIS if I use that instead ?

tafankuverymuch

If the old player isnt that important, just wire it up and see what happens
..
Worst case is that your throwing away something that probably shoulda been
discarded years ago anyhow..
If it just plays too fast then you can make a slower recording ;P..


http://www.national.com/mpf/LM/LM2575.html
throw in a diode, inductor, couple of caps, and a variable resistor and you
have a up to 1amp source :/..
Course, it might just be cheaper and easier to find some crappy used phone
charger or something that has a output close to 9v ..

 

[Zootal]

And why the 200ľF capacitor?

Why not 10?

Too small to absorb the variations

Why not 1000?

Way too big for the voltage.

--

With a 78xx, you don't need 200ľF on the output. 10 is more then adequate -
that is what the regulator is for. Be sure to put a 100nF or so cap in
parallel with it.

 

[chuckcar]

John Fields <jfields@austininstruments.com> wrote in
news:6r1k551jc5uasev62m1v0vl43vo2b2t6hd@4ax.com:

On Sat, 11 Jul 2009 21:50:55 +0000 (UTC), chuckcar <chuck@nil.car
wrote:

"ian field" <gangprobing.alien@ntlworld.com> wrote in
news:VZ56m.172$Ae3.44@newsfe01.ams2:


"chuckcar" <chuck@nil.car> wrote in message
news:Xns9C459893424AFchucknilcar@127.0.0.1...
"hhgggff" <ohu@klg.con> wrote in
newso16m.54775$OO7.27875@text.news.virginmedia.com:

My friends dad is building a Tardis for his grandson.

We have rigged up the blue flashing light using a 12 volt car
battery, we now need to sort out the sounds.

I was thinking of using an old cars cassette tape, but I have an old
9 volt portable cassette handy.

Will it burn down the TARDIS if I use that instead ?

The tape motor will run at the wrong speed for one. What you need is
a voltage regulator. A 7809 should do the trick. The 7800 series
convert DC voltages. Granted a transformer does it, but these handle
*much* wider voltage inputs and are tiny in comparison. A 7812 hooked
to the +12v connection with the other connection hooked to a 200
microfarad capacitor should give you a rock solid +9v out. You'll
need a piece of breadboard about 1" square to mount these on.


You should read up on a subject you know little about before giving
advice to others.

Considering the fact that my post is *far* more detailed than yours,
you're hardly a person to make such a judgement = along with your errors
detaied below.

---
The fact that your post was more "detailed" than Ian's doesn't mean that
his was wrong.
---

Even in older cassette recorders the motors had centrifugal speed
governors and modern ones have an IC speed controller (otherwise
they'd run slower and slower as the battery was used).

And none of this would burn out with 1 1/3 times the voltage input?
dubious.

---
Just conjecture without knowing more about the cassette recorder.
---

Your mention of transformers is misleading, without a "chopper"
circuit to convert DC into AC a transformer will burn out.

He's *using* a DC power source - a car battery. So a rectifier circuit
or an analogue is completely unncessary

---
But, since his application runs on DC, your reference to a transformer
was misleading since a transformer takes an AC input and supplies an AC
output which must then be rectified, filtered, and possibly regulated
before it can be used by the DC input device.

If, by "transformer", you meant an AC to DC converter, then your
terminology was wrong.
---

The OP is best advised to ask people who are equipped to give accurate
advice, such as the folk on News:sci.electronics.basics .

One *minor* correction of my post however - that *should* have been a
7809 not a 7812. This I picked up immediately when I read your reply. A
pretty basic error you didn't even notice. a 7812 converts *to* 12v
whereas a 7809 converts to 5v. Hence their names.

---
???

A 7809 converts to 9V, not 5V.

Message-ID: <Xns9C45EFC12936Cchucknilcar@127.0.0.1

In addition, not knowing the current requirements of the recorder, your
comment to build it on one square inch of breadboard (perfboard?) may
well be inconsistent with the heat-sinking required for the regulator.

And why the 200ľF capacitor?

Why not 10?

Too small to absorb the variations

Why not 1000?

Way too big for the voltage.

--
(setq (chuck nil) car(chuck) )

 

[John Fields]

On Mon, 13 Jul 2009 02:34:52 +0000 (UTC), chuckcar <chuck@nil.car>
wrote:

John Fields <jfields@austininstruments.com> wrote in
news:6r1k551jc5uasev62m1v0vl43vo2b2t6hd@4ax.com:

On Sat, 11 Jul 2009 21:50:55 +0000 (UTC), chuckcar <chuck@nil.car
wrote:

"ian field" <gangprobing.alien@ntlworld.com> wrote in
news:VZ56m.172$Ae3.44@newsfe01.ams2:


"chuckcar" <chuck@nil.car> wrote in message
news:Xns9C459893424AFchucknilcar@127.0.0.1...
"hhgggff" <ohu@klg.con> wrote in
newso16m.54775$OO7.27875@text.news.virginmedia.com:

My friends dad is building a Tardis for his grandson.

We have rigged up the blue flashing light using a 12 volt car
battery, we now need to sort out the sounds.

I was thinking of using an old cars cassette tape, but I have an old
9 volt portable cassette handy.

Will it burn down the TARDIS if I use that instead ?

The tape motor will run at the wrong speed for one. What you need is
a voltage regulator. A 7809 should do the trick. The 7800 series
convert DC voltages. Granted a transformer does it, but these handle
*much* wider voltage inputs and are tiny in comparison. A 7812 hooked
to the +12v connection with the other connection hooked to a 200
microfarad capacitor should give you a rock solid +9v out. You'll
need a piece of breadboard about 1" square to mount these on.


You should read up on a subject you know little about before giving
advice to others.

Considering the fact that my post is *far* more detailed than yours,
you're hardly a person to make such a judgement = along with your errors
detaied below.

---
The fact that your post was more "detailed" than Ian's doesn't mean that
his was wrong.
---

Even in older cassette recorders the motors had centrifugal speed
governors and modern ones have an IC speed controller (otherwise
they'd run slower and slower as the battery was used).

And none of this would burn out with 1 1/3 times the voltage input?
dubious.

---
Just conjecture without knowing more about the cassette recorder.
---

Your mention of transformers is misleading, without a "chopper"
circuit to convert DC into AC a transformer will burn out.

He's *using* a DC power source - a car battery. So a rectifier circuit
or an analogue is completely unncessary

---
But, since his application runs on DC, your reference to a transformer
was misleading since a transformer takes an AC input and supplies an AC
output which must then be rectified, filtered, and possibly regulated
before it can be used by the DC input device.

If, by "transformer", you meant an AC to DC converter, then your
terminology was wrong.
---

The OP is best advised to ask people who are equipped to give accurate
advice, such as the folk on News:sci.electronics.basics .

One *minor* correction of my post however - that *should* have been a
7809 not a 7812. This I picked up immediately when I read your reply. A
pretty basic error you didn't even notice. a 7812 converts *to* 12v
whereas a 7809 converts to 5v. Hence their names.

---
???

A 7809 converts to 9V, not 5V.

Message-ID: <Xns9C45EFC12936Cchucknilcar@127.0.0.1

In addition, not knowing the current requirements of the recorder, your
comment to build it on one square inch of breadboard (perfboard?) may
well be inconsistent with the heat-sinking required for the regulator.

And why the 200ľF capacitor?

Why not 10?

Too small to absorb the variations

---
What variations?
---

Why not 1000?

Way too big for the voltage.

---
Why?


JF

 

[Zootal]

"John Fields" <jfields@austininstruments.com> wrote in message
news:f8cm55htprevsh4nnnjhao8jlb3a9bu3k5@4ax.com...

On Mon, 13 Jul 2009 02:34:52 +0000 (UTC), chuckcar <chuck@nil.car
wrote:

John Fields <jfields@austininstruments.com> wrote in
news:6r1k551jc5uasev62m1v0vl43vo2b2t6hd@4ax.com:

On Sat, 11 Jul 2009 21:50:55 +0000 (UTC), chuckcar <chuck@nil.car
wrote:

"ian field" <gangprobing.alien@ntlworld.com> wrote in
news:VZ56m.172$Ae3.44@newsfe01.ams2:


"chuckcar" <chuck@nil.car> wrote in message
news:Xns9C459893424AFchucknilcar@127.0.0.1...
"hhgggff" <ohu@klg.con> wrote in
newso16m.54775$OO7.27875@text.news.virginmedia.com:

My friends dad is building a Tardis for his grandson.

We have rigged up the blue flashing light using a 12 volt car
battery, we now need to sort out the sounds.

I was thinking of using an old cars cassette tape, but I have an old
9 volt portable cassette handy.

Will it burn down the TARDIS if I use that instead ?

The tape motor will run at the wrong speed for one. What you need is
a voltage regulator. A 7809 should do the trick. The 7800 series
convert DC voltages. Granted a transformer does it, but these handle
*much* wider voltage inputs and are tiny in comparison. A 7812 hooked
to the +12v connection with the other connection hooked to a 200
microfarad capacitor should give you a rock solid +9v out. You'll
need a piece of breadboard about 1" square to mount these on.


You should read up on a subject you know little about before giving
advice to others.

Considering the fact that my post is *far* more detailed than yours,
you're hardly a person to make such a judgement = along with your errors
detaied below.

---
The fact that your post was more "detailed" than Ian's doesn't mean that
his was wrong.
---

Even in older cassette recorders the motors had centrifugal speed
governors and modern ones have an IC speed controller (otherwise
they'd run slower and slower as the battery was used).

And none of this would burn out with 1 1/3 times the voltage input?
dubious.

---
Just conjecture without knowing more about the cassette recorder.
---

Your mention of transformers is misleading, without a "chopper"
circuit to convert DC into AC a transformer will burn out.

He's *using* a DC power source - a car battery. So a rectifier circuit
or an analogue is completely unncessary

---
But, since his application runs on DC, your reference to a transformer
was misleading since a transformer takes an AC input and supplies an AC
output which must then be rectified, filtered, and possibly regulated
before it can be used by the DC input device.

If, by "transformer", you meant an AC to DC converter, then your
terminology was wrong.
---

The OP is best advised to ask people who are equipped to give accurate
advice, such as the folk on News:sci.electronics.basics .

One *minor* correction of my post however - that *should* have been a
7809 not a 7812. This I picked up immediately when I read your reply. A
pretty basic error you didn't even notice. a 7812 converts *to* 12v
whereas a 7809 converts to 5v. Hence their names.

---
???

A 7809 converts to 9V, not 5V.

Message-ID: <Xns9C45EFC12936Cchucknilcar@127.0.0.1

In addition, not knowing the current requirements of the recorder, your
comment to build it on one square inch of breadboard (perfboard?) may
well be inconsistent with the heat-sinking required for the regulator.

And why the 200ľF capacitor?

Why not 10?

Too small to absorb the variations

---
What variations?
---

Why not 1000?

Way too big for the voltage.

---
Why?

A 1000ľF cap on the output of a 78xx or 79xx regulator will work just fine.
It's just not necessary, but I don't think the power up surge of charging
the cap would hurt the regulator any, and once it's charged the circuit
should work fine.

If you are making a half million gizmos, you would want to use the smallest
cap you can get away with. Use a cap that cost a dollar less, and you just
saved a half million dollars.

 

[hhgggff]

I was thinking of using an old cars cassette tape, but I have an old 9
volt
portable cassette handy.

Well, In the end I just plugged it in and it works,correct speed.

tafankuverymuch

 

[ian field]

"hhgggff" <ohu@klg.con> wrote in message
news:cQ%7m.57494$OO7.26422@text.news.virginmedia.com...

I was thinking of using an old cars cassette tape, but I have an old 9
volt
portable cassette handy.

Well, In the end I just plugged it in and it works,correct speed.

tafankuverymuch

If you're running a 9V cassette player from a car battery, don't run it at
full volume - the audio output might be the weak link.