Need vtl5c3 for meatball & question..

[dubs]

Anyone want to sell me a pair of vactrol Vtl5c3 so I can build a meatball clone? or ldrs with same specs?
I can't buy them in Australia. I can payby paypal.
Do these need to be matched to make a meatball?

[Samuel]

doesn't smallbear stock them?

[mikeb]

SmallBear has them ... you should be able to get by with using the 'large' LDRs from Jaycar placed near rectangular red leds tho (with possibly some tweaks to the MB circuitry)....

Mike

[SaBer]

I made the Neutron with super-bright green LEDs and large LDRs in a shrink tube. The resistance went too low, so I had to add a 10k resistor in series. (It went down to 2k)

[Joep]

Small Bear is the place to be!

You can experiment with the LDR and Leds used in the Easyvibe, but you are on your own there.

The original Meatball uses separate LDR's and Led's btw.

Bye,

Joep

[dubs]

Thanks guys  there are two types of ldrs available in my local jaycar store:
1. Light Dependent Resistor (LDR)

Cadmium Sulphide (CdS) light dependent resistor cell. - Similar to Philips ORP12- Dark Resistance: min10M- Light Resistance: 48k - 140k- Max Dissipation: 30mW- Rise Time: (0~63%) 40mS- Decay Time: (100~37%) 10mS- Dimensions: 5.1mm x 4.3mm ±0.2- Lead spacing: 3.4mm

or a larger sized LDR

2. Light Dependent Resistor (LDR) - 8.5 x 10.1mm

Cadmium sulphide (CdS) light dependent resistor cell.
- Dark resistance: 0.5M ohm min.
- Light resistance: 2.8K ohm min 8.4K ohm max.
- Max dissipation: 100mW
- Rise time: (0-63%) 50mS
- Decay time: (100 - 37%) 40mS
- Dimensions: 8.5mm x 10.14mm
- Lead spacing: 7.68mm.



The specs of the vtl5c3 is 1k light resistance and 10M dark resistance. I assume the the first ldr (which is smaller)  is closest in spec  but will a higher light resistance affect the sound of the effect?

So with leds should I buy as bright as possible say something around 5000mcd?

[Joep]

The light resistance is the most important. The LDR is paralleled by a 220k resistor so at the maximum the total resistance is always 220k.

So I would use the second one. If the resistance is getting to low (this means the led is too bright) you can always change the 100Ohm serie resistors from the leds to a higher value.

Good luck,

Joep

[Nick123]

I  think that  attack  time  should  be  somewhere  around  5ms  and
decay  below  50ms  for  best  results.
Farnell  got  NSL32  and  NSL37V51  optoisolators.
NSL37V51  characteristics   are  identical  to  VTL5C3.
They  have  some  cheap  photoresistors -
NSL 19M51  and Fuji MPY54C569  look  like
the  best  choice  for  a  DIY  optoisolator.