Empathy List Archives

JH

Jerry Hancock

Sun, Jan 29, 2017 11:11 PM

One of the items I am having trouble modeling is a CLD, current limiting diode, MCL1302. The CLDs are used between he base and collectors on the output stage 2n2219 / 2n2905. I swapped them on the board with no impact on the problem. I can’t find CLDs in LTSPICE.

The other diode I can’t read and it is used cathode to cathode in a weird arrangement. The diode is roughly 1/2 the length (in this case height) of a 1n4148. It measures as a diode with .51V forward. I have a hard time telling if it actually has a cathode band. I haven’t pulled it out but I guess I’ll have to and put it under the microscope to see if there is a number on it. I have a lot of very low forward voltage switching diodes and Schottky type so I probably have it on-hand if I can get a number off of it.

I spent some more time on the circuit today.

By the way, even though the Parent company, was General Resistance, now Prime Technology, said they would sell me a CSA, they said they won’t share the schematic.

Thanks again.

One of the items I am having trouble modeling is a CLD, current limiting diode, MCL1302. The CLDs are used between he base and collectors on the output stage 2n2219 / 2n2905. I swapped them on the board with no impact on the problem. I can’t find CLDs in LTSPICE. The other diode I can’t read and it is used cathode to cathode in a weird arrangement. The diode is roughly 1/2 the length (in this case height) of a 1n4148. It measures as a diode with .51V forward. I have a hard time telling if it actually has a cathode band. I haven’t pulled it out but I guess I’ll have to and put it under the microscope to see if there is a number on it. I have a lot of very low forward voltage switching diodes and Schottky type so I probably have it on-hand if I can get a number off of it. I spent some more time on the circuit today. By the way, even though the Parent company, was General Resistance, now Prime Technology, said they would sell me a CSA, they said they won’t share the schematic. Thanks again.

BG

Bruce Griffiths

Sun, Jan 29, 2017 11:20 PM

A CLD is merely a JFET with the gate connected to the source.Sometimes a source resistor may be included with the gate connected to the opposite end of the resistor to the end connected to the source.
Bruce

On Monday, 30 January 2017 12:12 PM, Jerry Hancock <jerry@hanler.com> wrote:

One of the items I am having trouble modeling is a CLD, current limiting diode, MCL1302. The CLDs are used between he base and collectors on the output stage 2n2219 / 2n2905. I swapped them on the board with no impact on the problem. I can’t find CLDs in LTSPICE.

The other diode I can’t read and it is used cathode to cathode in a weird arrangement. The diode is roughly 1/2 the length (in this case height) of a 1n4148. It measures as a diode with .51V forward. I have a hard time telling if it actually has a cathode band. I haven’t pulled it out but I guess I’ll have to and put it under the microscope to see if there is a number on it. I have a lot of very low forward voltage switching diodes and Schottky type so I probably have it on-hand if I can get a number off of it.

I spent some more time on the circuit today.

By the way, even though the Parent company, was General Resistance, now Prime Technology, said they would sell me a CSA, they said they won’t share the schematic.

Thanks again.

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A CLD is merely a JFET with the gate connected to the source.Sometimes a source resistor may be included with the gate connected to the opposite end of the resistor to the end connected to the source. Bruce On Monday, 30 January 2017 12:12 PM, Jerry Hancock <jerry@hanler.com> wrote: One of the items I am having trouble modeling is a CLD, current limiting diode, MCL1302. The CLDs are used between he base and collectors on the output stage 2n2219 / 2n2905. I swapped them on the board with no impact on the problem. I can’t find CLDs in LTSPICE. The other diode I can’t read and it is used cathode to cathode in a weird arrangement. The diode is roughly 1/2 the length (in this case height) of a 1n4148. It measures as a diode with .51V forward. I have a hard time telling if it actually has a cathode band. I haven’t pulled it out but I guess I’ll have to and put it under the microscope to see if there is a number on it. I have a lot of very low forward voltage switching diodes and Schottky type so I probably have it on-hand if I can get a number off of it. I spent some more time on the circuit today. By the way, even though the Parent company, was General Resistance, now Prime Technology, said they would sell me a CSA, they said they won’t share the schematic. Thanks again. _______________________________________________ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.

JH

Jerry Hancock

Mon, Jan 30, 2017 1:04 AM

Yes, and I assume you would need an FET that acted like the CLD. I believe the MCL1302 is a 2mA device. I doubt I’[ll get the model working, which would be ideal.

On Jan 29, 2017, at 3:20 PM, Bruce Griffiths bruce.griffiths@xtra.co.nz wrote:

A CLD is merely a JFET with the gate connected to the source.Sometimes a source resistor may be included with the gate connected to the opposite end of the resistor to the end connected to the source.
Bruce

On Monday, 30 January 2017 12:12 PM, Jerry Hancock <jerry@hanler.com> wrote:

One of the items I am having trouble modeling is a CLD, current limiting diode, MCL1302. The CLDs are used between he base and collectors on the output stage 2n2219 / 2n2905. I swapped them on the board with no impact on the problem. I can’t find CLDs in LTSPICE.

The other diode I can’t read and it is used cathode to cathode in a weird arrangement. The diode is roughly 1/2 the length (in this case height) of a 1n4148. It measures as a diode with .51V forward. I have a hard time telling if it actually has a cathode band. I haven’t pulled it out but I guess I’ll have to and put it under the microscope to see if there is a number on it. I have a lot of very low forward voltage switching diodes and Schottky type so I probably have it on-hand if I can get a number off of it.

I spent some more time on the circuit today.

By the way, even though the Parent company, was General Resistance, now Prime Technology, said they would sell me a CSA, they said they won’t share the schematic.

Thanks again.

volt-nuts mailing list -- volt-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
and follow the instructions there.

Yes, and I assume you would need an FET that acted like the CLD. I believe the MCL1302 is a 2mA device. I doubt I’[ll get the model working, which would be ideal. > On Jan 29, 2017, at 3:20 PM, Bruce Griffiths <bruce.griffiths@xtra.co.nz> wrote: > > A CLD is merely a JFET with the gate connected to the source.Sometimes a source resistor may be included with the gate connected to the opposite end of the resistor to the end connected to the source. > Bruce > > On Monday, 30 January 2017 12:12 PM, Jerry Hancock <jerry@hanler.com> wrote: > > > One of the items I am having trouble modeling is a CLD, current limiting diode, MCL1302. The CLDs are used between he base and collectors on the output stage 2n2219 / 2n2905. I swapped them on the board with no impact on the problem. I can’t find CLDs in LTSPICE. > > The other diode I can’t read and it is used cathode to cathode in a weird arrangement. The diode is roughly 1/2 the length (in this case height) of a 1n4148. It measures as a diode with .51V forward. I have a hard time telling if it actually has a cathode band. I haven’t pulled it out but I guess I’ll have to and put it under the microscope to see if there is a number on it. I have a lot of very low forward voltage switching diodes and Schottky type so I probably have it on-hand if I can get a number off of it. > > I spent some more time on the circuit today. > > By the way, even though the Parent company, was General Resistance, now Prime Technology, said they would sell me a CSA, they said they won’t share the schematic. > > Thanks again. > _______________________________________________ > volt-nuts mailing list -- volt-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > and follow the instructions there. > > > > _______________________________________________ > volt-nuts mailing list -- volt-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > and follow the instructions there.

CS

Charles Steinmetz

Mon, Jan 30, 2017 2:38 AM

Jerry wrote:

One of the items I am having trouble modeling is a CLD, current limiting diode, MCL1302.

CLDs are almost always operated in saturation, so a behavioral current
source of the appropriate value should model it just fine for your needs
(spec for the MCL1302 is 2mA +/- 0.6mA -- as you can see, hardly
precision devices).

CLDs are nothing more than JFETs operating at Idss, so you can also
model them with a JFET with its gate tied to its source. Of course, you
have to try different FET models until you find one with the appropriate
Idss, or play with source resistors to lower the saturation current of a
FET with somewhat higher Idss.

But if you insist, Central Semi has models of its CLDs on its web site:

https://www.centralsemi.com/content/engineering/spicemodels/index.php

Central makes a direct substitute (the CMCL1302), but does not seem to
have a Spice model for that particular one. The CCL2000 is another 2mA
CLD, with similar specs (but a somewhat tighter current variance spec).
You can find its P-Spice model here:

http://www.centralsemi.com/docs/csm/CCLP.LIB

I'm sure that model would be more than close enough for your purposes.

Best regards

Charles

Jerry wrote: > One of the items I am having trouble modeling is a CLD, current limiting diode, MCL1302. CLDs are almost always operated in saturation, so a behavioral current source of the appropriate value should model it just fine for your needs (spec for the MCL1302 is 2mA +/- 0.6mA -- as you can see, hardly precision devices). CLDs are nothing more than JFETs operating at Idss, so you can also model them with a JFET with its gate tied to its source. Of course, you have to try different FET models until you find one with the appropriate Idss, or play with source resistors to lower the saturation current of a FET with somewhat higher Idss. But if you insist, Central Semi has models of its CLDs on its web site: <https://www.centralsemi.com/content/engineering/spicemodels/index.php> Central makes a direct substitute (the CMCL1302), but does not seem to have a Spice model for that particular one. The CCL2000 is another 2mA CLD, with similar specs (but a somewhat tighter current variance spec). You can find its P-Spice model here: <http://www.centralsemi.com/docs/csm/CCLP.LIB> I'm sure that model would be more than close enough for your purposes. Best regards Charles

JH

Jerry Hancock

Mon, Jan 30, 2017 3:51 AM

Charles, thank you! Very helpful, as everyone has been.

On Jan 29, 2017, at 6:38 PM, Charles Steinmetz csteinmetz@yandex.com wrote:

Jerry wrote:

One of the items I am having trouble modeling is a CLD, current limiting diode, MCL1302.

CLDs are almost always operated in saturation, so a behavioral current source of the appropriate value should model it just fine for your needs (spec for the MCL1302 is 2mA +/- 0.6mA -- as you can see, hardly precision devices).

CLDs are nothing more than JFETs operating at Idss, so you can also model them with a JFET with its gate tied to its source. Of course, you have to try different FET models until you find one with the appropriate Idss, or play with source resistors to lower the saturation current of a FET with somewhat higher Idss.

But if you insist, Central Semi has models of its CLDs on its web site:

https://www.centralsemi.com/content/engineering/spicemodels/index.php

Central makes a direct substitute (the CMCL1302), but does not seem to have a Spice model for that particular one. The CCL2000 is another 2mA CLD, with similar specs (but a somewhat tighter current variance spec). You can find its P-Spice model here:

http://www.centralsemi.com/docs/csm/CCLP.LIB

I'm sure that model would be more than close enough for your purposes.

Best regards

Charles

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Charles, thank you! Very helpful, as everyone has been. > On Jan 29, 2017, at 6:38 PM, Charles Steinmetz <csteinmetz@yandex.com> wrote: > > Jerry wrote: > >> One of the items I am having trouble modeling is a CLD, current limiting diode, MCL1302. > > CLDs are almost always operated in saturation, so a behavioral current source of the appropriate value should model it just fine for your needs (spec for the MCL1302 is 2mA +/- 0.6mA -- as you can see, hardly precision devices). > > CLDs are nothing more than JFETs operating at Idss, so you can also model them with a JFET with its gate tied to its source. Of course, you have to try different FET models until you find one with the appropriate Idss, or play with source resistors to lower the saturation current of a FET with somewhat higher Idss. > > But if you insist, Central Semi has models of its CLDs on its web site: > > <https://www.centralsemi.com/content/engineering/spicemodels/index.php> > > Central makes a direct substitute (the CMCL1302), but does not seem to have a Spice model for that particular one. The CCL2000 is another 2mA CLD, with similar specs (but a somewhat tighter current variance spec). You can find its P-Spice model here: > > <http://www.centralsemi.com/docs/csm/CCLP.LIB> > > I'm sure that model would be more than close enough for your purposes. > > Best regards > > Charles > > > _______________________________________________ > volt-nuts mailing list -- volt-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > and follow the instructions there.

JH

Jerry Hancock

Mon, Jan 30, 2017 4:31 AM

Well, you aren’t going to believe this, but I’ve checked the circuit about 10 times now and it looks pretty good. I then used Charles advice and imported the CCL2000 CLD. I ran the model and it swung to the negative rail to almost the exact voltage I am getting with the real circuit of -13.979V. I know I still have errors in the model but I find this to be pretty funny.

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