Digital Voltage Levels...

Archiver

Hello Group,

········Can any ofyou pro's tell us what voltage levels are allowed, or OK to input intologic gates?· Specifically, what is the maximum allowed withoutdamage risk?· These signals are not input into a Stamp directly, butrather through some logic gates first.

Thank you,

Tim

Timothy Medema
CrystaLite, Inc.
3307 CedarSt.··················(425)745-6000·· 800-666-6065
Everett, WA98201···············Fax[noparse]:([/noparse]425) 257-0232

www.crystaliteinc.com···········timm@crystaliteinc.com


The information transmitted is intended onlyfor the person or entity to whom it is addressed and may containconfidential and/or privileged material.· Any review,retransmission, dissemination or other use of, or taking of any action inreliance upon, this information by persons or entities other than theintended recipient is prohibited.· If you received this in error,please contact the sender and delete the material from anycomputer.

Archiver

If you're talking about 5V logic devices, data sheets usually specify the minimum level required as·HI. Often the maximum is not listed. CMOS chips will usually handle a bit more than TTL, and I think you'll find numbers like·7 and 5.5V. It's not always safe to make assumptions here, especially if you're over 5.5V. I would check individual data sheets online (fastest way). BTW, have you thought about current?
C.L.

ps: we all expect free lemonade.....

---

Original Message

---

From: Timothy Medema [noparse][[/noparse]mailto:timm@crystaliteinc.com]
Sent: Monday, May 07, 2001 3:46 PM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] Digital Voltage Levels...


Hello Group,

········Can any of you pro's tell us what voltage levels are allowed, or OK to input into logic gates?· Specifically, what is the maximum allowed without damage risk?· These signals are not input into a Stamp directly, but rather through some logic gates first.

Thank you,

Tim

Timothy Medema
CrystaLite, Inc.
3307 Cedar St.··················(425) 745-6000·· 800-666-6065
Everett, WA 98201···············Fax: (425) 257-0232

www.crystaliteinc.com···········timm@crystaliteinc.com


The information transmitted is intended only for the person or entity to whom it is addressed and may contain confidential and/or privileged material.· Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited.· If you received this in error, please contact the sender and delete the material from any computer.
Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.

Archiver

Chris,

········Yes, I amthinking about 5V logic devices.· I have a sensor that outputs a HIlogic level of about 12V and am not sure if that is OK to input into a 5Vlogic device without conditioning and no, I haven't looked into thecurrent issue yet - suggestions?

Thanks,· do you prefer regular or pink lemonade?

Tim


At 04:46 PM 5/7/2001 -0400, you wrote:

Ifyou're talking about 5V logic devices, data sheets usually specify theminimum level required as HI. Often the maximum is not listed. CMOS chipswill usually handle a bit more than TTL, and I think you'll find numberslike 7 and 5.5V. It's not always safe to make assumptions here,especially if you're over 5.5V. I would check individual data sheetsonline (fastest way). BTW, have you thought about current?
C.L.

ps: we all expect freelemonade.....

---

OriginalMessage

---

From: Timothy Medema[noparse]/noparse][url=mailto:timm@crystaliteinc.com]mailto:timm@crystaliteinc.com[/url
Sent: Monday, May 07, 2001 3:46 PM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] Digital Voltage Levels...


Hello Group,

········Can any ofyou pro's tell us what voltage levels are allowed, or OK to input intologic gates?· Specifically, what is the maximum allowed withoutdamage risk?· These signals are not input into a Stamp directly, butrather through some logic gates first.

Thank you,

Tim

Timothy Medema
CrystaLite, Inc.
3307 CedarSt.··················(425)745-6000·· 800-666-6065
Everett, WA98201···············Fax[noparse]:([/noparse]425) 257-0232

www.crystaliteinc.com···········timm@crystaliteinc.com


The information transmitted is intended onlyfor the person or entity to whom it is addressed and may containconfidential and/or privileged material.· Any review,retransmission, dissemination or other use of, or taking of any action inreliance upon, this information by persons or entities other than theintended recipient is prohibited.· If you received this in error,please contact the sender and delete the material from anycomputer.
Your use of Yahoo! Groups is subject to theYahoo! Terms ofService.

Your use of Yahoo! Groups is subject to theYahoo! Terms ofService.

Timothy Medema
CrystaLite, Inc.
3307 CedarSt.··················(425)745-6000·· 800-666-6065
Everett, WA98201···············Fax[noparse]:([/noparse]425) 257-0232

www.crystaliteinc.com···········timm@crystaliteinc.com


The information transmitted is intended onlyfor the person or entity to whom it is addressed and may containconfidential and/or privileged material.· Any review,retransmission, dissemination or other use of, or taking of any action inreliance upon, this information by persons or entities other than theintended recipient is prohibited.· If you received this in error,please contact the sender and delete the material from anycomputer.

Archiver

Tim, there are many ways to skin a cat - and this is no exception. I like simple methods, and the one that comes to mind is to make a voltage divider with a pair of resistors in series, which you can tap from the center to give you the 5V you need.·I wouldn't even try the 12V directly, although, again, there are some devices that can handle it. Without knowing all the specifics, the voltage divider will be safe and fairly efficient.

·················If both resistors are the same value:

····································· R1·············· R2
Sensor Out

---

/\/\/\/\/\/\

---

/\/\/\/\/\/

---

Gnd
(12VDC)···································· |
················································6V

The added value of your resistors must be chosen so that the current does not exceed the rated limit of the sensor output. I=E/R. ie: if you used 10k resistors, for a total of 20k, your current would be 12/20,000, or .6mA. If you want a voltage other than exactly 1/2, or 6V in this case, the simple calculation is·· Vout = Vin·x· (R2 / R1 + R2).
Of course, you'll need to figure the power for each resistor, so you know what size to use in Watts. You can get close enough by using I=E/R again, using E, or voltage for each of the two resistors, not the total this time. If you had 5V across R2, which is, say 1k Ohms, you'd have 5 mA of current (I). The power in Watts = I squared x R. So it would be W=5mA squared X 1000, or .025 Watts. A 1/4 W resistor would handle 10 x that power, an 1/8 W, 5x.

Does that help?
Chris

ps:
Regular

---

Original Message

---

From: Timothy Medema [noparse][[/noparse]mailto:timm@crystaliteinc.com]
Sent: Monday, May 07, 2001 4:52 PM
To: basicstamps@yahoogroups.com
Subject: RE: [noparse][[/noparse]basicstamps] Digital Voltage Levels...


Chris,

········Yes, I am thinking about 5V logic devices.· I have a sensor that outputs a HI logic level of about 12V and am not sure if that is OK to input into a 5V logic device without conditioning and no, I haven't looked into the current issue yet - suggestions?

Thanks,· do you prefer regular or pink lemonade?

Tim


At 04:46 PM 5/7/2001 -0400, you wrote:

If you're talking about 5V logic devices, data sheets usually specify the minimum level required as HI. Often the maximum is not listed. CMOS chips will usually handle a bit more than TTL, and I think you'll find numbers like 7 and 5.5V. It's not always safe to make assumptions here, especially if you're over 5.5V. I would check individual data sheets online (fastest way). BTW, have you thought about current?
C.L.

ps: we all expect free lemonade.....

---

Original Message

---

From: Timothy Medema [noparse]/noparse][url=mailto:timm@crystaliteinc.com]mailto:timm@crystaliteinc.com[/url
Sent: Monday, May 07, 2001 3:46 PM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] Digital Voltage Levels...


Hello Group,

········Can any of you pro's tell us what voltage levels are allowed, or OK to input into logic gates?· Specifically, what is the maximum allowed without damage risk?· These signals are not input into a Stamp directly, but rather through some logic gates first.

Thank you,

Tim

Timothy Medema
CrystaLite, Inc.
3307 Cedar St.··················(425) 745-6000·· 800-666-6065
Everett, WA 98201···············Fax: (425) 257-0232

www.crystaliteinc.com···········timm@crystaliteinc.com


The information transmitted is intended only for the person or entity to whom it is addressed and may contain confidential and/or privileged material.· Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited.· If you received this in error, please contact the sender and delete the material from any computer.
Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.

Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.

Timothy Medema
CrystaLite, Inc.
3307 Cedar St.··················(425) 745-6000·· 800-666-6065
Everett, WA 98201···············Fax: (425) 257-0232

www.crystaliteinc.com···········timm@crystaliteinc.com


The information transmitted is intended only for the person or entity to whom it is addressed and may contain confidential and/or privileged material.· Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited.· If you received this in error, please contact the sender and delete the material from any computer.
Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.

Archiver

Chris,

········That helpsa bunch, and honestly I'm a little embarrassed that i didn't think ofit.· Sometimes the obvious is the hardest to see!· I appreciateyour help very much.· A simple and effective solution.

Tim


At 05:27 PM 5/7/2001 -0400, you wrote:

Tim,there are many ways to skin a cat - and this is no exception. I likesimple methods, and the one that comes to mind is to make a voltagedivider with a pair of resistors in series, which you can tap from thecenter to give you the 5V you need. I wouldn't even try the 12V directly,although, again, there are some devices that can handle it. Withoutknowing all the specifics, the voltage divider will be safe and fairlyefficient.

················If both resistors are the same value:

·····································R1··············R2
SensorOut

---

/\/\/\/\/\/\

---

/\/\/\/\/\/

---

Gnd
(12VDC)····································|
···············································6V

The added value of yourresistors must be chosen so that the current does not exceed the ratedlimit of the sensor output. I=E/R. ie: if you used 10k resistors, for atotal of 20k, your current would be 12/20,000, or .6mA. If you want avoltage other than exactly 1/2, or 6V in this case, the simplecalculation is·· Vout = Vin x· (R2 / R1 + R2).
Of course, you'll need tofigure the power for each resistor, so you know what size to use inWatts. You can get close enough by using I=E/R again, using E, or voltagefor each of the two resistors, not the total this time. If you had 5Vacross R2, which is, say 1k Ohms, you'd have 5 mA of current (I). Thepower in Watts = I squared x R. So it would be W=5mA squared X 1000, or.025 Watts. A 1/4 W resistor would handle 10 x that power, an 1/8 W,5x.

Does that help?
Chris

ps:
Regular

---

OriginalMessage

---

From: Timothy Medema[noparse]/noparse][url=mailto:timm@crystaliteinc.com]mailto:timm@crystaliteinc.com[/url
Sent: Monday, May 07, 2001 4:52 PM
To: basicstamps@yahoogroups.com
Subject: RE: [noparse][[/noparse]basicstamps] Digital Voltage Levels...


Chris,

········Yes, I amthinking about 5V logic devices.· I have a sensor that outputs a HIlogic level of about 12V and am not sure if that is OK to input into a 5Vlogic device without conditioning and no, I haven't looked into thecurrent issue yet - suggestions?

Thanks,· do you prefer regular or pink lemonade?

Tim


At 04:46 PM 5/7/2001 -0400, you wrote:

Ifyou're talking about 5V logic devices, data sheets usually specify theminimum level required as HI. Often the maximum is not listed. CMOS chipswill usually handle a bit more than TTL, and I think you'll find numberslike 7 and 5.5V. It's not always safe to make assumptions here,especially if you're over 5.5V. I would check individual data sheetsonline (fastest way). BTW, have you thought about current?
C.L.

ps: we all expect freelemonade.....

---

OriginalMessage

---

From: Timothy Medema[noparse]/noparse][url=mailto:timm@crystaliteinc.com]mailto:timm@crystaliteinc.com[/url
Sent: Monday, May 07, 2001 3:46 PM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] Digital Voltage Levels...


Hello Group,

········Can any ofyou pro's tell us what voltage levels are allowed, or OK to input intologic gates?· Specifically, what is the maximum allowed withoutdamage risk?· These signals are not input into a Stamp directly, butrather through some logic gates first.

Thank you,

Tim

Timothy Medema
CrystaLite, Inc.
3307 CedarSt.··················(425)745-6000·· 800-666-6065
Everett, WA98201···············Fax[noparse]:([/noparse]425) 257-0232

www.crystaliteinc.com···········timm@crystaliteinc.com


The information transmitted is intended onlyfor the person or entity to whom it is addressed and may containconfidential and/or privileged material.· Any review,retransmission, dissemination or other use of, or taking of any action inreliance upon, this information by persons or entities other than theintended recipient is prohibited.· If you received this in error,please contact the sender and delete the material from anycomputer.
Your use of Yahoo! Groups is subject to theYahoo! Terms ofService.

Your use of Yahoo! Groups is subject to theYahoo! Terms ofService.

Timothy Medema
CrystaLite, Inc.
3307 CedarSt.··················(425)745-6000·· 800-666-6065
Everett, WA98201···············Fax[noparse]:([/noparse]425) 257-0232

www.crystaliteinc.com···········timm@crystaliteinc.com


The information transmitted is intended onlyfor the person or entity to whom it is addressed and may containconfidential and/or privileged material.· Any review,retransmission, dissemination or other use of, or taking of any action inreliance upon, this information by persons or entities other than theintended recipient is prohibited.· If you received this in error,please contact the sender and delete the material from anycomputer.
Your use of Yahoo! Groups is subject to theYahoo! Terms ofService.

Your use of Yahoo! Groups is subject to theYahoo! Terms ofService.

Timothy Medema
CrystaLite, Inc.
3307 CedarSt.··················(425)745-6000·· 800-666-6065
Everett, WA98201···············Fax[noparse]:([/noparse]425) 257-0232

www.crystaliteinc.com···········timm@crystaliteinc.com


The information transmitted is intended onlyfor the person or entity to whom it is addressed and may containconfidential and/or privileged material.· Any review,retransmission, dissemination or other use of, or taking of any action inreliance upon, this information by persons or entities other than theintended recipient is prohibited.· If you received this in error,please contact the sender and delete the material from anycomputer.