Dropping a few tenths of a volt problem

How would you know? You don't know how to do it. ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| San Tan Valley, AZ 85142   Skype: Contacts Only  |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 
              
I love to cook with wine.     Sometimes I even put it in the food.

--

John Larkin         Highland Technology, Inc 

jlarkin att highlandtechnology dott com 
http://www.highlandtechnology.com

Just tried it again, but I've done it before. The as-is LT Spice library schmitt inverter outputs +1 volt with a 1 ohm output impedance.

--

John Larkin         Highland Technology, Inc 

jlarkin att highlandtechnology dott com 
http://www.highlandtechnology.com

Whoopee! Just a wee bit late to the game are we ?>:-} ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| San Tan Valley, AZ 85142   Skype: Contacts Only  |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 
              
I love to cook with wine.     Sometimes I even put it in the food.

In AoE, 2ed, page 557: pulse generator circuits.

Four parts vs your ten, and works better.

--

John Larkin                  Highland Technology Inc 
www.highlandtechnology.com   jlarkin at highlandtechnology dot com    

Precision electronic instrumentation

Right click on inverter and add a spice line..

Vhigh 5

This will make it 5 voltage logic. Rout 100

Will make it 100 ohm impedance, etc..

Some may want to alter the low voltage

Vlow .7

Etc..

Jamie

Sure. Go nuts.

I'll take a look at it later, John, I have to leave now in a hurry and won't be back for 7 hours or so...

It's less fussy about the power supply,

--
Neither the pheasant plucker, nor the pheasant plucker's son. 


--- news://freenews.netfront.net/ - complaints: news@netfront.net ---

yeah, and gound isn't 0v.

--
Neither the pheasant plucker, nor the pheasant plucker's son.

On Sat, 22 Mar 2014 09:20:08 +0100, Cursitor Doom wrote:

--- The supply voltage for the Schmitt triggers is set at 5V, and the hysteresis is set at Vcc/2 + 0.5V and Vcc/2 - 0.5V.

Version 4 SHEET 1 4748 4196 WIRE -6032 3472 -6112 3472 WIRE -5520 3472 -6032 3472 WIRE -5456 3472 -5520 3472 WIRE -5456 3520 -5456 3472 WIRE -6032 3552 -6032 3472 WIRE -5760 3568 -5936 3568 WIRE -5520 3568 -5520 3472 WIRE -5520 3568 -5696 3568 WIRE -4992 3648 -5056 3648 WIRE -4880 3648 -4992 3648 WIRE -4736 3648 -4880 3648 WIRE -4640 3648 -4736 3648 WIRE -4544 3648 -4640 3648 WIRE -5936 3664 -5936 3568 WIRE -5792 3664 -5936 3664 WIRE -5520 3664 -5520 3568 WIRE -5520 3664 -5568 3664 WIRE -4992 3696 -4992 3648 WIRE -4736 3696 -4736 3648 WIRE -4640 3696 -4640 3648 WIRE -6032 3728 -6032 3632 WIRE -5792 3728 -6032 3728 WIRE -5456 3728 -5456 3600 WIRE -5456 3728 -5568 3728 WIRE -6704 3760 -7136 3760 WIRE -6640 3760 -6704 3760 WIRE -5792 3792 -5872 3792 WIRE -5456 3792 -5456 3728 WIRE -5456 3792 -5568 3792 WIRE -6704 3824 -6704 3760 WIRE -6032 3840 -6032 3728 WIRE -5792 3856 -5824 3856 WIRE -4880 3856 -4880 3648 WIRE -4544 3856 -4544 3648 WIRE -5200 3872 -5232 3872 WIRE -5088 3872 -5120 3872 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SYMATTR Value trise 50n tfall 50n vhigh 5V vh 0.5 SYMBOL voltage -6976 3968 R0 WINDOW 123 0 0 Left 2 WINDOW 39 24 124 Left 2 WINDOW 3 24 96 Invisible 2 SYMATTR InstName V1 SYMATTR Value PULSE(0 3.9 0 10n 10n 5m 300m 500) SYMBOL diode -6768 3920 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName D1 SYMATTR Value 1N4148 SYMBOL res -6720 3808 R0 SYMATTR InstName R1 SYMATTR Value 180k SYMBOL cap -6720 3984 R0 SYMATTR InstName C1 SYMATTR Value 80n SYMBOL res -6544 3952 R0 SYMATTR InstName R2 SYMATTR Value 400k SYMBOL voltage -7136 3968 R0 WINDOW 123 0 0 Left 2 WINDOW 39 24 124 Left 2 SYMATTR InstName V2 SYMATTR Value 5 SYMBOL res -4752 3792 M180 WINDOW 0 -59 74 Left 2 WINDOW 3 -65 46 Left 2 SYMATTR InstName R3 SYMATTR Value 1meg SYMBOL cap -4720 3984 M0 SYMATTR InstName C2 SYMATTR Value 10n SYMBOL diode -4768 3872 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName D3 SYMATTR Value 1N4148 SYMBOL res -4624 3680 M0 WINDOW 0 -49 36 Left 2 WINDOW 3 -64 66 Left 2 SYMATTR InstName R6 SYMATTR Value 1meg SYMBOL res -4624 3952 M0 WINDOW 0 -50 33 Left 2 WINDOW 3 -69 61 Left 2 SYMATTR InstName R7 SYMATTR Value 2meg SYMBOL Comparators\\LT1017 -4880 3888 R0 WINDOW 0 -59 -54 Left 2 WINDOW 3 -99 52 Left 2 SYMATTR InstName U3A SYMBOL res -5008 3952 R0 SYMATTR InstName R8 SYMATTR Value 5100 SYMBOL res -5008 3680 R0 SYMATTR InstName R9 SYMATTR Value 100k SYMBOL Comparators\\LT1017 -4544 3888 R0 WINDOW 0 -58 -52 Left 2 WINDOW 3 -91 51 Left 2 SYMATTR InstName U3B SYMBOL res -5104 3952 R0 WINDOW 0 -52 40 Left 2 WINDOW 3 -61 74 Left 2 SYMATTR InstName R13 SYMATTR Value 100k SYMBOL res -5104 3856 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R14 SYMATTR Value 10k SYMBOL Misc\\NE555 -5680 3760 R0 SYMATTR InstName U5 SYMBOL res -6048 3648 M180 WINDOW 0 36 76 Left 2 WINDOW 3 36 40 Left 2 SYMATTR InstName R16 SYMATTR Value 10k SYMBOL res -5440 3504 M0 WINDOW 0 -48 32 Left 2 WINDOW 3 -71 65 Left 2 SYMATTR InstName R17 SYMATTR Value 1meg SYMBOL cap -5440 3968 M0 WINDOW 0 -25 6 Left 2 WINDOW 3 -55 32 Left 2 SYMATTR InstName C5 SYMATTR Value 10n SYMBOL cap -5760 3552 M90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C7

SYMBOL Digital\\schmitt -6624 3872 R0 WINDOW 3 8 44 Invisible 2 SYMATTR InstName A2 SYMATTR Value trise 50n tfall 50n vhigh 5V vh 0.5 SYMBOL npn -6096 3840 R0 SYMATTR InstName Q1 SYMATTR Value 2N3904 SYMBOL res -6176 4048 M180 WINDOW 0 36 76 Left 2 WINDOW 3 36 40 Left 2 SYMATTR InstName R15 SYMATTR Value 100k SYMBOL res -6288 3872 M90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R18 SYMATTR Value 10k TEXT -7120 4128 Left 2 !.tran 0 1.4s 0 .1m TEXT -5408 3600 Right 2 ;Rt TEXT -5416 4032 Right 2 ;Ct TEXT -6904 4128 Left 2 ;VARIOUS PULSE STRETCHERS TEXT -6904 4160 Left 2 ;JOHN FIELDS, 22 MARCH 2014

You're still barking up the wrong tree. The correct question is: 'Why does this circuit not work on all voltages known to be good for the logic elements?'.

The power supply has a remarkably large internal resistance (more than usual dry batteries, which I guess you're using).

For a so limp power feed, do you have any by-pass capacitors?

More questions: What should the circuit do if the incoming pulse rate exceeds the maximum allowed by the extension time?

--

Tauno Voipio

Much better. Add a two-transistor monostable.

--

-TV

Cursitor's circuit has problems because his input doesn't reach the hysteresis points of the 74HC14... read some of the early posts to get calibrated.

In fact I don't think 74HCxx parts are speedy enough for very narrow pulses. Probably should pick a faster family. ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| San Tan Valley, AZ 85142   Skype: Contacts Only  |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 
              
I love to cook with wine.     Sometimes I even put it in the food.

. . .

--
I've done as much as I care to for the time being. 

Instead of barking orders, why don't you try your hand at it?

Another Larkin emulator?

Another one to ignore. ...Jim Thompson

-- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San Tan Valley, AZ 85142 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at

| 1962 | I love to cook with wine. Sometimes I even put it in the food.

How's that neon model coming along? Is it anything like a real neon lamp yet?

I'll check back in a month or so... wouldn't want to stress you too much.

--

John Larkin                  Highland Technology Inc 
www.highlandtechnology.com   jlarkin at highlandtechnology dot com    

Precision electronic instrumentation

If I read correctly, his pulses were in the millisecond range, no big deal.

The pulse stretcher is dangerous in his application, as it turns quiet when the pulse rate is high enough.

--

-TV