Twin T circuit wanted
in [Basics]
|
From: default on 6 Jun 2010 23:01 On Sun, 6 Jun 2010 18:05:57 +0100, "john jardine" <zen177928(a)zen.co.uk> wrote: > >"default" <default(a)defaulter.net> wrote in message >news:9dhk06dltvk703cdpri3dt91bvjnbjr6cf(a)4ax.com... >> Can someone supply a single transistor circuit that will give a damped >> sine wave when a pulse is applied? to emulate a bell sound >> -- > > ,---------, > | |5V > .-. - > | | --- > | |4k7 | > '-' === > | GND > ,-----------------------------o-----o > | | | Damped Sine > | .-.1M o-------o Out > | | | | -> ~1Vpp > | | | | > | 10k 10k '-' | > | ___ ___ || | |/ > o---|___|---o--|___|--o--||---o---| BC547 > | | | || |> > | --- | 10u | > | ---100n | o------ > | | | | | > | === | | --- > | || || | | --- 10u > '----||-----o----||---' | | > || | || .-. | > 10n .-. 10n | | .-."Q"Pot > | | | | | |<-. > | | '-' | | |220 > '-'1k 1k | '-' | > -> | | | | > PIC o------------' === === === > Narrow Pulse GND GND GND > to Ring > >(created by AACircuit v1.28 beta 10/06/04 www.tech-chat.de) > Thanks I'll give it a try --
From: John Larkin on 6 Jun 2010 23:05 On Sun, 06 Jun 2010 22:58:28 -0400, default <default(a)defaulter.net> wrote: >On Sun, 06 Jun 2010 10:14:04 -0700, John Larkin ><jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: > >>On Sun, 06 Jun 2010 08:41:19 -0400, default <default(a)defaulter.net> >>wrote: >> >>>On Sat, 05 Jun 2010 10:06:01 -0700, John Larkin >>><jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >>> >>>>On Sat, 05 Jun 2010 10:49:18 -0400, default <default(a)defaulter.net> >>>>wrote: >>>> >>>>>On Sat, 05 Jun 2010 09:54:04 -0400, Jamie >>>>><jamie_ka1lpa_not_valid_after_ka1lpa_(a)charter.net> wrote: >>>>> >>>>>>default wrote: >>>>>>> Can someone supply a single transistor circuit that will give a damped >>>>>>> sine wave when a pulse is applied? to emulate a bell sound >>>>>>Damped? Do you mean compressed to a sequare wave? >>>>>> >>>>>> >>>>>> You can do a 180 degree phase shift in a double T RC network how >>>>>>ever, that produces a sine wave. etc.. >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> Feed back --||---+---||----+---||-----Base of tranny.. >>>>>> | | >>>>>> | | >>>>>> R R >>>>>> | | >>>>>> com com >>>>>> >>>>>>ect. >>>>>> >>>>>> >>>>>> >>>>>Damped as in decaying, just like a bell. >>>>> >>>>>Seems to me John Larkin or Jim Thompson posted something like this a >>>>>long time ago. Searching didn't find exactly what I want. I'm >>>>>building a set of mechanical chimes but wanted something to use until >>>>>I work out the kinks - and test the pic timing. >>>> >>>>I did a bell simulator once, but I used several, three or four, >>>>damped-ringing LC resonators. A single one didn't sound very >>>>bell-like. Turns out that bells have a number of nearby resonant >>>>modes, each with not-quite harmonics. Complex. >>>> >>>>The thing I did drove loudspeakers in the bow of a ship to go >>>>bong-bong-bong every 30 seconds in the fog, so a crew guy didn't have >>>>to stand there all night whacking a bell. >>>> >>>>Why not use the PIC and a dac? The code would be interesting. >>>> >>>>John >>>> >>>I want the finished product to have mechanical chimes, the electronic >>>bells (twelve, with the ability to strike 2-4 at the same time, or >>>strike one while another is still ringing down) >>> >>>To get the timing for the music I thought a little excursion into >>>electronic bells would be helpful, because the mechanical parts are >>>unwieldy, and I haven't committed to a mechanical design I'm satisfied >>>with - then I thought this might also make a killer doorbell . . . a >>>bit of "mission creep" is setting in. >> >>To simulate the chimes, why not a PC with a sound card? There must be >>tons of suitable software around. >> >>John >> >> >I don't want to simulate, I want hardware making sound. > >A PC for a door bell is overkill - and the real thing will be >mechanical that is a design goal. Sorry. I thought you wanted to electronically simulate the sounds before building the mechanical version. John
From: John Larkin on 6 Jun 2010 23:24 On Sun, 6 Jun 2010 18:05:57 +0100, "john jardine" <zen177928(a)zen.co.uk> wrote: > >"default" <default(a)defaulter.net> wrote in message >news:9dhk06dltvk703cdpri3dt91bvjnbjr6cf(a)4ax.com... >> Can someone supply a single transistor circuit that will give a damped >> sine wave when a pulse is applied? to emulate a bell sound >> -- > > ,---------, > | |5V > .-. - > | | --- > | |4k7 | > '-' === > | GND > ,-----------------------------o-----o > | | | Damped Sine > | .-.1M o-------o Out > | | | | -> ~1Vpp > | | | | > | 10k 10k '-' | > | ___ ___ || | |/ > o---|___|---o--|___|--o--||---o---| BC547 > | | | || |> > | --- | 10u | > | ---100n | o------ > | | | | | > | === | | --- > | || || | | --- 10u > '----||-----o----||---' | | > || | || .-. | > 10n .-. 10n | | .-."Q"Pot > | | | | | |<-. > | | '-' | | |220 > '-'1k 1k | '-' | > -> | | | | > PIC o------------' === === === > Narrow Pulse GND GND GND > to Ring > >(created by AACircuit v1.28 beta 10/06/04 www.tech-chat.de) > Here's my ship's fog bell generator, as I remember it. The decay was set by tapering off the supply voltage to 4 or maybe 5 LC oscillators, so Q didn't matter. It sounded pretty good. ftp://jjlarkin.lmi.net/Ships_Bell.JPG A refinement would be to have a separate decay rate for each oscillator, since some harmonics of a real bell fade at different rates from others. Yikes, I remember thousands of schematics but can never recall where I left my glasses. John
From: Phil Hobbs on 7 Jun 2010 00:41 John Larkin wrote: > On Sun, 6 Jun 2010 18:05:57 +0100, "john jardine" > <zen177928(a)zen.co.uk> wrote: > >> "default" <default(a)defaulter.net> wrote in message >> news:9dhk06dltvk703cdpri3dt91bvjnbjr6cf(a)4ax.com... >>> Can someone supply a single transistor circuit that will give a damped >>> sine wave when a pulse is applied? to emulate a bell sound >>> -- >> ,---------, >> | |5V >> .-. - >> | | --- >> | |4k7 | >> '-' === >> | GND >> ,-----------------------------o-----o >> | | | Damped Sine >> | .-.1M o-------o Out >> | | | | -> ~1Vpp >> | | | | >> | 10k 10k '-' | >> | ___ ___ || | |/ >> o---|___|---o--|___|--o--||---o---| BC547 >> | | | || |> >> | --- | 10u | >> | ---100n | o------ >> | | | | | >> | === | | --- >> | || || | | --- 10u >> '----||-----o----||---' | | >> || | || .-. | >> 10n .-. 10n | | .-."Q"Pot >> | | | | | |<-. >> | | '-' | | |220 >> '-'1k 1k | '-' | >> -> | | | | >> PIC o------------' === === === >> Narrow Pulse GND GND GND >> to Ring >> >> (created by AACircuit v1.28 beta 10/06/04 www.tech-chat.de) >> > > > Here's my ship's fog bell generator, as I remember it. The decay was > set by tapering off the supply voltage to 4 or maybe 5 LC oscillators, > so Q didn't matter. It sounded pretty good. > > ftp://jjlarkin.lmi.net/Ships_Bell.JPG > > A refinement would be to have a separate decay rate for each > oscillator, since some harmonics of a real bell fade at different > rates from others. > > Yikes, I remember thousands of schematics but can never recall where I > left my glasses. Order 10 pairs from Zenni Optical and leave them everywhere. 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: tm on 7 Jun 2010 00:51
"John Larkin" <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote in message news:35po06tdq5g8shn21k3n9pto73i5vm3vjf(a)4ax.com... > On Sun, 6 Jun 2010 18:05:57 +0100, "john jardine" > <zen177928(a)zen.co.uk> wrote: > >> >>"default" <default(a)defaulter.net> wrote in message >>news:9dhk06dltvk703cdpri3dt91bvjnbjr6cf(a)4ax.com... >>> Can someone supply a single transistor circuit that will give a damped >>> sine wave when a pulse is applied? to emulate a bell sound >>> -- >> >> ,---------, >> | |5V >> .-. - >> | | --- >> | |4k7 | >> '-' === >> | GND >> ,-----------------------------o-----o >> | | | Damped Sine >> | .-.1M o-------o Out >> | | | | -> ~1Vpp >> | | | | >> | 10k 10k '-' | >> | ___ ___ || | |/ >> o---|___|---o--|___|--o--||---o---| BC547 >> | | | || |> >> | --- | 10u | >> | ---100n | o------ >> | | | | | >> | === | | --- >> | || || | | --- 10u >> '----||-----o----||---' | | >> || | || .-. | >> 10n .-. 10n | | .-."Q"Pot >> | | | | | |<-. >> | | '-' | | |220 >> '-'1k 1k | '-' | >> -> | | | | >> PIC o------------' === === === >> Narrow Pulse GND GND GND >> to Ring >> >>(created by AACircuit v1.28 beta 10/06/04 www.tech-chat.de) >> > > > Here's my ship's fog bell generator, as I remember it. The decay was > set by tapering off the supply voltage to 4 or maybe 5 LC oscillators, > so Q didn't matter. It sounded pretty good. > > ftp://jjlarkin.lmi.net/Ships_Bell.JPG > > A refinement would be to have a separate decay rate for each > oscillator, since some harmonics of a real bell fade at different > rates from others. > > Yikes, I remember thousands of schematics but can never recall where I > left my glasses. > > John > > In a like request, how about a GQ alarm? I restored a GQ generator on a WW2 sub that used a geared motor to trigger a damped oscillator with mechanical contacts. Of course it was all tubes. T |