Cheap TOYs (ages 8 +) offer AC Signal Gen:. Here's a couple 'Tear-Downs'

[RJSV]

Hello:
   Some previous post had mentioned this; Using cheapo 'Drugstore / Boxstore' TOYS, for generating various TEST signals.  (I will look for that).

   Here, in photo, I've just gone and attached test clip leads, lazy, but those 2 little thin (speaker) wires, I cut, getting to the nub.

   For AC signals, audio is approx 0.25 Volts, that sort of range, giving 'Piano' sounds, for example. With no speaker, the AC volts is higher; at approx 0.41 Volts, RMS.
   I never like 'scratchy', so including a crude High-Cut switch, with capacitor / resistor.
   Plus, a capacitor in series with output helps control and wiring 'Boo boos' like putting + 5 VDC supply on the things audio speaker output
   Headphone jack, stereo has just a 'Mono' mode.
The whole thing, is just providing an easy risk 'Lab' tool.

[RJSV]

Here is Another 'Under $ 10 dollar' Toy:
   This, mind-blowing example, of old art meets new, is BOTH Audio and Visual, providing rapid moving screen by way of, possibly Patented, a segmented screen, having vertical ' stripe' lens effect;
   The moving screen, has vertical focus stripes, accepting then rejecting, each 'alternate'. That could be something, from 1910...
   For motion, a WIND-UP, and completely Old School music box plays musical tune, plus it 'winds' that special screen Diarama.
For example, A bee is harassing bear, and you can watch the back and forth bee, and bear's face squinting.
  Plus, very special, That music box features a 'Flying Speed Control', that's a spinning 'prop' that keeps speed correct...

[Circlotron]

Clean your camera lens.

[RJSV]

Thank you, I did a few swipes, warm water, but will do the citrus swipes,.  Ya know...I never thought about the front glass.
Will check when sunny, tomorrow.

[RJSV]

Here's a view (photo), featuring a typical 'FLY' regulator (if I got that approx right).  The 'Flying' portion spins, deliberately causing (considerable) drag, and this getting close enough to 'terminal', or maximum speed vs air resistance drag.
   Camera doesn't show; that's a lot of black plastic, so no contrast.
   That rotating 'FLY' I est is rotating at about 10 to 30 revolutions per second.
At 30, that's 30 X 60 = 1800 rpm.
And, at roughly 36 mSec per rev,  that divides out to 1 mSec per 10° or one milli-Second per ten degrees.
...When you start going smaller than that, like 5 degrees of ARC, that's in hundreds of MicroSeconds...

[RJSV]

Here is, potentially frivolous idea, as I've realized, that baby tinkle-tones, with clever screen has no 'apparent' application(s), as a test device.
  So, to 'generate', real-world electronic signals, takes a couple easy steps;
   First, you could always create your own track, going around a little 'diarama' loop you've made.
Reflecting, you need for a sensor,. .something like a little round CDS cell; they are resistance output, and around 20 kOhms was one 'threshold' I've seen.
What I mean is, another toy I had was using a CDS sensor, motion sense would cause the CDS cell to go around near 20 kOhms, up and down.
That was what this other toy had been using, as an optical 'trigger' or perhaps 'wiggle' sensitive, around the
(whatever) level of light, getting near to that sensor disk.
   It's a two wire device; has a flat disk shape, (approx like a hearing-aid batt.)
Of course, 'optical' methods might get interesting, on that fast-turning FLY regulator.
e

[RJSV]

Now, if you could please, see photo; That's a
 'Chirping and gesturing BIRD'.
   For sensing, I replaced the optical sensor, with a resistor, 26 kOhms, apparently gives fast trigger, responding, by setting the 'Chirp-Sing and move head and beak', into (timed) action.

   The movement, is VIA two solenoids, very light stuff, really.; The solenoids are approx 7 mm diameter, a bunch of fine magnet wire turns.
Actual SOLENOID signals...Could be just an audio channel, streamed out along with bird song channel.
Audio effect, is similar to a thump-thump, although it is basic Solenoid action, of electric current to magnetic force.

[Haenk]

PLEASE (<- capital letters) use a different camera. The pictures literally hurt my eyes, they look like a submerged VTECH kiddy camera from the early 2000s. Awful.

 

[RJSV]

   Sorry, that's a typical brand, ALCATEL, very cheap,
plus with hand shakes, But I see your point...
(Actually, had some 'more' blurry, amateur photos, I'll hold those back).
Have gotten other 'irritated comments', so will keep off the visuals, for now.
Sincere thanks.

[RJSV]

   With that 'moving diarhama' run by wind-up being 'electric free', it is interesting, to think about a possible 'Player Piano' type roll, activating a 'Lane' that a CDS photo-cell is pointing at.
(Activating another Toy; a Singing and gesturing Bird.)

   Those vertical focusing stripes cause approx 8 times per second 'reversal', optically.  Something less than 1 mm, perhaps 600 uM (microns).  The diarhama is moved, with 4 inches of the paper loop, per screen, as taking up 22 seconds of scroll time.
That's 5 1/2 seconds, per inch.

[RJSV]

   The point is, at 8 vertical focus 'stripes' per second, that's the speed the moving diarhama encounters each (stationary) focus stripe, (at 600 microns each lens).

   What happens is, thicker lines, in the moving landscape / diarhama, just do a little 'shimmy' as they move...while thinner, more fragile lines, can have a 'moving dots' neon-like action look to them, motion being either upwards, or downwards moving dots.
   But it's hard to figure it out;
Best I can figure, is the 'stripe-Lens'  effect is to alternately accept, then reject the subject matter (diarhama feature).
That way, very quick motions, up to 4 X per second, even, can be 'simulated', by the simple motion across the special, striped LENs screen.

   At approx 5 seconds, per inch travel, that's 5 sec per 25 mm or 1 second per 5 mm travel.
Doing the math that way, it's; 5 mm per second, and divided by 0.6 mm 'Lens width';
That's approx 8 'Lens Events' per second, meaning something behind the lens would alternately pop in and out of view, as the relative positions change.
That's of course, very ballpark rough est.

[RJSV]

   On that special SCREEN material, the current thought is that the thin vertical 'stripe' Lens material is in sets of 4.  That is, any line smaller in width to (that 'cell' size) of 2.4 mm will flicker, as the relative motion of background diarhama happens.
   For the marquee moving lights effect, You obviously can't just do even & odd, as that would just bounce back and forth, appearance-wise.
With sets of 3, in a row, you can sequence '1, 2, 3, and with a sequencing string of 30, that would have 10 lamps on, any given moment.
That moving background loop might even have SETs consisting of FOUR-Lens groupings.
   
   Then there is the question, of how some thin diagonal 'arcs' display a motion (illusion) upwards, while other arc sweeps have downward apparent movement.

Sorry, I know this might not appear, directly, as a piece of TEST EQ. but bear with it...
(The 'toy' has great child-safety aspects...no electric parts!)

[RJSV]

I had not tried, using that AUDIO output from the TOY PIANO but, at 0.41 V RMS that's a pretty good 1.1 volts, peak to peak. The toy doesn't have any sofisticated 'ground' or anything formal, so just using the piano audio (speaker) output, both wires, for casual experiments is fine, LED doesn't care anyway, wherever the potential DC comes from...
   Using a 'deep blue' efficient LED gave fairly bright flashes, to the rythum and cadence, of the brief little toy 'song'.
(Had thought, BLUE LED needed like 2.8 V?).

   So now that's good news, as that TOY PIANO can, also function as an OPTICAL SOURCE for pulses, just what I like to have !

[RJSV]

   For a function, giving an output created by a Paper Strip-Chart, a CDS photo resistor (had been) considered.  Trying by placing that Cds light sensor right directly up against the rolling diarhama loop
(Please see reply #2 for details, on the continuous loop.

[RJSV]

The CDs cell only changed, from approx 1310 ohms, to 1360 ohms, a resistive change that might create a 30 milliVolt difference, for a comparitor to distinguish.

   Out in 3-D space, you can get approx 300 ohms, up to 20 kOhms in total dark.

Idea was; a student could 'program' a few different tracks, on a custom paper loop.
Then, the student's creation, can be made to activate LEDs, (of course), but also motors and lightweight solenoids.
  You would have, say, 4 different parallel 'LANES'.
that a student would fill in, with felt pen.

[RJSV]

It's a little bit dumb-ass, but I'm finding a bit of gratification, playing with the features in that rolling paper 'Screen image Loop'.
   Testing the limits, of what a suspended Cds photocell can produce, a la Paper Strip Chart, only it is for producing 'control' waveforms.  A student can create a sort-of 'density' track, for producing varying photocell output, as the paper chart loop rolls past sensor location.
   Results, on the somewhat slow (>1 mSec Cds response ): You can get a variation of about 1K, pulsing up, to approx 2.0 Kohms when cell is over the black test bars.  You can also see; the faster impulse representing bars do not cause a 'quality' sensor output, being too fast.
Just trying things out. (Note that a regular strip chart is based on a 'Y' offset, for (X,Y) graphing, while this depicts an ink 'density', along the chart time axis).


   Older school electronic consumer products often include interesting mix, of mechanical devices, or even just the packaging, can be novel.
This 'Wind-up' TOY even emits motor like audio sounds, as it turns it's main-spring and drives a gear train.

(Child safety has big influence on what makes it into the package.)

[Circlotron]

Testing the limits, of what a suspended Cds photocell can produce,

That explains it. I was wondering what you were using to produce the photographs in this thread.

[RJSV]

Sorry, that's several comments have come in.
Tried 'citrus' clean wipes, plus dry wipe..
(Might be scuffed, but it's only 18 months new.)
Picture details don't matter, but I don't want to be rude.
There is enough info, to supplement my, often schetchy narrative.
   What is: Apple phone price minus 'Alcatel' ($89)?
PM me, and I'll instruct how / where to send donations.

Simply stopping CAMERA use, hasn't been enough, for decent, helpful, readable posts.
But I've been asking about:
   Do some folks just buy a stand-alone 'Zoom' camera, maybe Bluetooth interface?
   Will a Bluetooth camera interface to my smartphone ? The cellphone does do some wifi, I'm thinking a 'Zoom' style camera, perhaps wifi comm link, to my smart phone (Alcatel cheapo).
  Lots of people doing that, lately.

[AVGresponding]

Does Bluetooth support a high enough bit-rate for images? I'm not sure it does. I recall it takes forever to share pics over bt.

There are tons of cheap usb cameras out there, to connect to phone or pc; I use a cheap endoscope (~$10) and a cheap microscope (~$15), the only thing you have to watch out for is truly dire quality software (sometimes it also has malware bundled in for free...).

[RJSV]

OK, got some more info, regarding that musical TOY, with various instrument selections, and 'Song Demo' button.
   The tactile Dome-press keys are arranged in typical 3 row, by 8 column, from the 'blob encased' processor, so I'm also wondering, if any use can had, for the scanning signal employed there?  (I've got a Tektronix '465, the house owner made available).
I'm expecting, perhaps, some keyboard scan rate, maybe around 3X per second.  So, with a 2N2222 buffer that isolated signal could be 'repurposed', as part of the simple (cheapo) set of 'AC / audio Signal Generator's outputs possible, as a serious, but inexpensive Lab tools...
I believe the 'piano' range is somewhere near 500hz to 900 hz, at about 1.2 V ac rms.
First thing, is adding a volume control, and headphone jack, including a screw terminal block.

I'm a big fan, of this kind of 'make-do', low risk utilization. Call it 'poor snobbery', I suppose.
I'm learning all kinds of technician stuff, the Oscilloscope triggering functions, and all at low risk, (except wearing eye protection, when fabricating).