Twin T circuit wanted
in [Basics]
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From: David Eather on 7 Jun 2010 02:31 On 6/06/2010 10:45 PM, default wrote: > On Sun, 06 Jun 2010 07:04:50 +1000, David Eather<eather(a)tpg.com.au> > wrote: > >> On 5/06/2010 11:54 PM, Jamie 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. >>> >>> >>> >>> >> >> If you reduce the gain of the amplifier portion of the circuit you will >> get what you want > > Yeah. I tried that with a square wave and fet amplitude control, with > a little L-C massaging on the output it doesn't sound bad, but it is > too much hardware. Seems to me, back in the day, they used single > twin T oscillators to get the sounds of drums, base drum and tom-tom, > as well as bells from fairly simple one transistor circuits. Don't use the amplitude control. set it with a pot and then leave it alone.
From: Jasen Betts on 7 Jun 2010 04:43 On 2010-06-06, default <default(a)defaulter.net> wrote: > 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) write a simulator that produces ABC or MIDI format(etc) and render it as sound on a PC. Or compoose in MIDI or ABC and write a converter, or interpreter. --- news://freenews.netfront.net/ - complaints: news(a)netfront.net ---
From: Jan Panteltje on 7 Jun 2010 06:27 On a sunny day (Sun, 06 Jun 2010 20:24:00 -0700) it happened John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote in <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 Record a real bell? hehe Those little modules tha trecord a few seconds are cheap. The sound of those bells may even be available on some sound effect sites for free.
From: John Fields on 7 Jun 2010 07:47 On Sun, 06 Jun 2010 20:24:00 -0700, John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> 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. --- Apparently, since what he asked for was a: "single transistor circuit". ;) JF
From: John Larkin on 7 Jun 2010 09:47
On Mon, 07 Jun 2010 06:47:07 -0500, John Fields <jfields(a)austininstruments.com> wrote: >On Sun, 06 Jun 2010 20:24:00 -0700, John Larkin ><jjlarkin(a)highNOTlandTHIStechnologyPART.com> 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. > >--- >Apparently, since what he asked for was a: "single transistor >circuit". ;) > >JF This is a discussion group, and the subject was circuits that simulate bells. You posted none. Why is that? A single-oscillator version of my thing doesn't sound as good, but it is sort of bell-like. It's a cinch you're not going to simulate 5 damped oscillation modes with one trensistor. [1] Show us your single-transistor bell simulator circuit. John [1] the original touch-tone telephone managed to make controlled-amplitude DTMF tone pairs from a single transistor, sort of defying conventional wisdom about oscillator modes. |