ElectroVibe IC1 ?

[nkt$275]

On the board above the LT1054 and 47R there is a shape like a transistor with three holes no label. In another thread I saw the shape labeled as IC1. Since there is no build doc -
What component is this ?

 

[Big Monk]

On the board above the LT1054 and 47R there is a shape like a transistor with three holes no label. In another thread I saw the shape labeled as IC1. Since there is no build doc -
What component is this ?

It’s the voltage regulator for the 15vDC portions of the circuit.

 

[nkt$275]

I am not familiar with that component.
Or I should say ordering the proper component. I know what a voltage regulator is but not the specific one for the ElectroVibe circuit.
I have the board finished except that component.
Thank You ! ! !

 

[nkt$275]

Tayda -
MC78L15A
15v. 0.1A TO-92
Is this correct ?

 

[Mcknib]

That's the beast or search 78L15

Voltage regulators with the 78 prefix are positive output 79 negative output you want positive

 

[JamieJ]

I think I used a 78L12 for mine which was recommended here somewhere.

 

[nkt$275]

Thank You ! ! !

 

[music6000]

I think I used a 78L12 for mine which was recommended here somewhere.

78L12 is the correct value, 78L15 creates ticking noise when tried in Builds.
7371 bulb and 7532 photocell.

 

[zgrav]

so the regulated portion is 12V instead of 15V. right?

 

[nkt$275]

Who is a good source for 7532 photocells ?
I have heard photocells are as finicky as
germanium transistors.
How are you choosing/calibrating them ?
What are the best/acceptable measurements ?

 

[Big Monk]

Who is a good source for 7532 photocells ?
I have heard photocells are as finicky as
germanium transistors.
How are you choosing/calibrating them ?
What are the best/acceptable measurements ?

I used 9203 from Jameco that has the same specs as the 9203 from Small Bear. The 9203 from Digikey has slightly different specs and the 7532 are actually closer in spec to the Digikey 9203 than to the Jameco/SBE 9203.

I don’t know of anyone sort photocells for use in this circuit. Put them in and tweak the gain and offset until it sounds best.

 

[fig]

Has anyone ever tried a photo-transistor in place of a photo-cell?

 

[nkt$275]

The 7371 bulb from Digikey hits the lid of the 1590BB enclosure. I saw another member had the same problem. There is no place to gain space. The Dual pots are snug with the board.
Solutions ?
1. Different bulb - is a 7219 compatible performance wise ? Or another ?
2. Different enclosure - Tayda 1590BB2

 

[Big Monk]

Can you not close the lid? I know mine touched but just barely. Are you sure the Speed pots are fully seated?

Sounds dumb but did you make sure to take off any extra washers from the pots?

My bulb still touches bit the lid closes just fine.

 

[nkt$275]

No extra washers. Lid will close.
But touches glass bulb. Just thought perhaps
not a good situation. ? ? ?
By the way Big Monk I have read several of your threads … and enjoy them very much.
Thank You !

 

[Big Monk]

No extra washers. Lid will close.
But touches glass bulb. Just thought perhaps
not a good situation. ? ? ?

I've had no issues with performance but I am a bedroom player. I'd have misgivings if it was out on the road or at gigs each weekend but it has not caused me any lost sleep or tone yet.

By the way Big Monk I have read several of your threads … and enjoy them very much.
Thank You !

Much appreciated!

 

[ntuncer]

Hi, do we plug 9vdc in electrovibe? I saw that the original uses 24v.

Cheers

 

[Big Monk]

Hi, do we plug 9vdc in electrovibe?

Cheers

Yup.

 

[Bricksnbeatles]

Has anyone ever tried a photo-transistor in place of a photo-cell?

I’ve thought about finding a way to use phototransistors in a circuit, but I still don’t fully understand them. I’ve thought about testing out photodiodes as clippers in the second clipping stage of a circuit with two clipping stages, with led used as the clippers in the first clipping stage. I still don’t fully understand photodiodes outside of a light-measurement circuit (ie, I have no idea how to use photodiodes outside of a textbook application), but a few quick tests I did a few years ago did suggest that they work as clippers, albeit in a pretty strange and potentially undesirable way.

 

[nkt$275]

Just curious -
For the Electrovibe which voltage regulator is better for the circuit ?
1) Current Quiescent 3 mA with PSRR 51 dB
2) Current Quiescent 6 mA with PSRR 39 dB