MOC7811 output swing limits?

Thread Starter

onlyvinod56

Joined Oct 14, 2008
363
Hello,

I have connected MOC7811 as per this circuit

When there is an obstacle, the output voltage is 4.2V.
When there is no obstacle, the output voltage is 4V.

Is it not possible to get the output from 0V to 5V????
 

ian123

Joined Aug 24, 2011
73
Are you working under a light source . I had that problem years back found light from my desk was causing the base to turn on
 

SgtWookie

Joined Jul 17, 2007
22,210
Are you certain that your voltages and resistance values are as shown in the schematic?

Measure your supply voltage with your components connected. If the supply voltage is not 5v, then you need to say what it is.

The 360 Ohm resistor may need to be adjusted if your voltage is different than 5v.
If your output load is heavy, you may need to amplify the output signal. You don't say what it is.
 

bertus

Joined Apr 5, 2008
20,102
Hello,

The current through the IR led is to low.
In the datasheet 20 - 30 mA is given, you have about 12 mA.

See the attached datasheet

Bertus
 

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