Circuit Challenge of the Day
in [Design]
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From: Jim Thompson on 18 Dec 2009 11:59 Circuit Challenge of the Day The following circuit... http://analog-innovations.com/SED/RampGenerator_Amusement.pdf is a ramp generator. It is easy to see how the upper trip point circuitry causes discharge of the ramp. But what causes the turn-around at the bottom? ...Jim Thompson -- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 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.
From: Phil Hobbs on 18 Dec 2009 12:46 Jim Thompson wrote: > Circuit Challenge of the Day > > The following circuit... > > http://analog-innovations.com/SED/RampGenerator_Amusement.pdf > > is a ramp generator. > > It is easy to see how the upper trip point circuitry causes discharge > of the ramp. > > But what causes the turn-around at the bottom? > > ...Jim Thompson As the collector current of Q1 drops to zero, its VBEsat drops below the level needed to keep Q4 turned on, due to that 200 ohm resistor dropping 100 mV. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal ElectroOptical Innovations 55 Orchard Rd Briarcliff Manor NY 10510 845-480-2058 hobbs at electrooptical dot net http://electrooptical.net
From: Jim Thompson on 18 Dec 2009 12:49 On Fri, 18 Dec 2009 12:46:20 -0500, Phil Hobbs <pcdhSpamMeSenseless(a)electrooptical.net> wrote: >Jim Thompson wrote: >> Circuit Challenge of the Day >> >> The following circuit... >> >> http://analog-innovations.com/SED/RampGenerator_Amusement.pdf >> >> is a ramp generator. >> >> It is easy to see how the upper trip point circuitry causes discharge >> of the ramp. >> >> But what causes the turn-around at the bottom? >> >> ...Jim Thompson >As the collector current of Q1 drops to zero, its VBEsat drops below the >level needed to keep Q4 turned on, due to that 200 ohm resistor dropping >100 mV. > >Cheers > >Phil Hobbs Shhhhhh !-) ...Jim Thompson -- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | Help save the environment! Please dispose of socialism properly!
From: TTman on 18 Dec 2009 16:01 "Jim Thompson" <To-Email-Use-The-Envelope-Icon(a)My-Web-Site.com/Snicker> wrote in message news:90dni5dpk2qgvmio5f82piv3ov07u0sm9u(a)4ax.com... > Circuit Challenge of the Day > > The following circuit... > > http://analog-innovations.com/SED/RampGenerator_Amusement.pdf > > is a ramp generator. > > It is easy to see how the upper trip point circuitry causes discharge > of the ramp. Is it ? > > But what causes the turn-around at the bottom? > Errr R3? lol
From: Jim Thompson on 18 Dec 2009 17:19
On Fri, 18 Dec 2009 21:01:33 -0000, "TTman" <someone.pc(a)ntlworld.com> wrote: > >"Jim Thompson" <To-Email-Use-The-Envelope-Icon(a)My-Web-Site.com/Snicker> >wrote in message news:90dni5dpk2qgvmio5f82piv3ov07u0sm9u(a)4ax.com... >> Circuit Challenge of the Day >> >> The following circuit... >> >> http://analog-innovations.com/SED/RampGenerator_Amusement.pdf >> >> is a ramp generator. >> >> It is easy to see how the upper trip point circuitry causes discharge >> of the ramp. > >Is it ? > >> >> But what causes the turn-around at the bottom? >> > >Errr R3? lol > Errrr! How? This isn't multiple choice... Tell me a sequential set of events that causes Q1 to turn off when the ramp bottoms. ...Jim Thompson -- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | Help save the environment! Please dispose of socialism properly! |