Can you get 110 milliamps from a 9V battery?
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I have a 9V transistor battery connected thru a 7805 5V regulator to
provide 5V to a chip that requires 110 milliamps (a General
Instruments Allophone Speech chip). Per the 7805 data sheet, I have a
.3 uF cap on the input side and .1 uF cap on the output (5V side) of
the regulator. I have the ground pin of the regulator connected to Vss
on my BS2 Homework board. The 'run' light on the BS2 Homework board
blinks on and after 15 seconds turns off - which appears to be the
correct execution time for my program. During troubleshooting this
circuit, I found the output of the regulator is only .04V when
connected to the chip. So either there's a short in my circuit or this
chip is pulling too much current from my 5V source.
Last qustion - is there a simple way to verify a crystal is working
(without the use of a scope)?
provide 5V to a chip that requires 110 milliamps (a General
Instruments Allophone Speech chip). Per the 7805 data sheet, I have a
.3 uF cap on the input side and .1 uF cap on the output (5V side) of
the regulator. I have the ground pin of the regulator connected to Vss
on my BS2 Homework board. The 'run' light on the BS2 Homework board
blinks on and after 15 seconds turns off - which appears to be the
correct execution time for my program. During troubleshooting this
circuit, I found the output of the regulator is only .04V when
connected to the chip. So either there's a short in my circuit or this
chip is pulling too much current from my 5V source.
Last qustion - is there a simple way to verify a crystal is working
(without the use of a scope)?
Comments
a short.
Disconnect everything from the 7805's Vout and make sure you are getting 5v.
Then start reconnecting the circuit in steps while periodically rechecking
Vout.
-- Al Margolis, founder
www.hobbyengineering.com
The technology builder's source for kits, components, supplies, tools, books
and education.
Original Message
From: fab4442003 [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=UpaPWGm_jpRLDacc_4Nj_cT1BAgUm0v6oPXzqJjVIJ9-TmVJ5F9IdTfQXiQAM0EiRTNZJ4T09jB52DA]fab4442003@y...[/url
Sent: Sunday, January 11, 2004 6:15 PM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] Can you get 110 milliamps from a 9V battery?
I have a 9V transistor battery connected thru a 7805 5V regulator to
provide 5V to a chip that requires 110 milliamps (a General
Instruments Allophone Speech chip). Per the 7805 data sheet, I have a
.3 uF cap on the input side and .1 uF cap on the output (5V side) of
the regulator. I have the ground pin of the regulator connected to Vss
on my BS2 Homework board. The 'run' light on the BS2 Homework board
blinks on and after 15 seconds turns off - which appears to be the
correct execution time for my program. During troubleshooting this
circuit, I found the output of the regulator is only .04V when
connected to the chip. So either there's a short in my circuit or this
chip is pulling too much current from my 5V source.
Last qustion - is there a simple way to verify a crystal is working
(without the use of a scope)?
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At 2:14 AM +0000 1/12/04, fab4442003 wrote:
>I have a 9V transistor battery connected thru a 7805 5V regulator to
>provide 5V to a chip that requires 110 milliamps (a General
>Instruments Allophone Speech chip). Per the 7805 data sheet, I have a
>.3 uF cap on the input side and .1 uF cap on the output (5V side) of
>the regulator. I have the ground pin of the regulator connected to Vss
>on my BS2 Homework board. The 'run' light on the BS2 Homework board
>blinks on and after 15 seconds turns off - which appears to be the
>correct execution time for my program. During troubleshooting this
>circuit, I found the output of the regulator is only .04V when
>connected to the chip. So either there's a short in my circuit or this
>chip is pulling too much current from my 5V source.
--
Chuck Britton Education is what is left when
britton@n... you have forgotten everything
North Carolina School of Science & Math you learned in school.
(919) 416-2762 Albert Einstein, 1936
20 year old Radio Shack breadboard - the SIDE rails on both edges of
the breadboard are connected down the entire length of the breadboard!
Time to rewire this thing...
> 110 ma is only .11A, so you aren't drawing too much current, unless
you have
> a short.
>
> Disconnect everything from the 7805's Vout and make sure you are
getting 5v.
> Then start reconnecting the circuit in steps while periodically
rechecking
> Vout.
>
> -- Al Margolis, founder
> www.hobbyengineering.com
> The technology builder's source for kits, components, supplies,
tools, books
> and education.
>
>
Original Message
> From: fab4442003 [noparse][[/noparse]mailto:fab4442003@y...]
> Sent: Sunday, January 11, 2004 6:15 PM
> To: basicstamps@yahoogroups.com
> Subject: [noparse][[/noparse]basicstamps] Can you get 110 milliamps from a 9V battery?
>
>
> I have a 9V transistor battery connected thru a 7805 5V regulator to
> provide 5V to a chip that requires 110 milliamps (a General
> Instruments Allophone Speech chip). Per the 7805 data sheet, I have a
> .3 uF cap on the input side and .1 uF cap on the output (5V side) of
> the regulator. I have the ground pin of the regulator connected to Vss
> on my BS2 Homework board. The 'run' light on the BS2 Homework board
> blinks on and after 15 seconds turns off - which appears to be the
> correct execution time for my program. During troubleshooting this
> circuit, I found the output of the regulator is only .04V when
> connected to the chip. So either there's a short in my circuit or this
> chip is pulling too much current from my 5V source.
>
> Last qustion - is there a simple way to verify a crystal is working
> (without the use of a scope)?