Hi, I am attempting to remote control a motor with the HOLTEK ht12e encoder and ht12d decoder. Here is a copy of an email I have sent to EMECO the Australian agents for HOLTEK. Does anybody have any suggestions as to why it is not working?
"HI, I am attempting to remote control a 240vac motor using phase control of the motor speed. No problems with hardwiring of the circuit.
It is possible that latching of the data output of 12d may be the problem. It shouldn’t be as the data is only supposed to be latched until new data is received.
The data is being applied from a microcontroller. Here is an example of the MCU output which is giving me an invalid transmission signal (led not lighting up) at the 12d.
After zero crossing of the mains the motor is off for 4500us then on for 4500us before turning off until the next on signal. This is giving me an invalid transmission signal for the 12d.
It may not be a problem with the 12d but the transistor I am using to amplify the signal. The mains is 50hz.
What is your opinion? Testing done with light globe which doesn’t light at all."

 

Does anybody have any suggestions as to why it is not working?

Not a clue without a circuit diagram.

 

Not a clue without a circuit diagram.

... and a datasheet for the Holtek component.

 

... and a datasheet for the Holtek component.

I’m fortunate there, having used the device before.

 

Not a clue without a circuit diagram.

Good luck getting any info from this TS. This is about the fourth or fifth thread started on the same subject about using the ht12. Never posted a schematic and does not respond to questions asked like, "did you check this or measure that".

 

I’m fortunate there, having used the device before.

Hi Mr Salts, As you have used the device before do you think the problem is in the latching of the data? No problems switching globe to 200ms on and off. You have to amplify the signal as the 12D can only supply 1ma at 4.5v. I am using a random phase triac opto coupler moc3023 which needs 5ma.
You may not have used the 12d and 12e at the speeds I need. The amplifier is a npn transistor which may be too slow coming out of saturation.
I would point out to others on this forum that I would love to post a schematic but I can't because LTSpice uses .asc files which are not accepted on this forum.

 

post a schematic but I can't because LTSpice uses .asc files which are not accepted on this forum.

Print it to a pdf and post the pdf. Or do a screen capture and post a jpg.

 

Hello,
Are you using data pins D8/9/10/11 as outputs?
If you have an MCU to control, why not use it as a decoder?

 

Hi Mr Salts, As you have used the device before do you think the problem is in the latching of the data? No problems switching globe to 200ms on and off. You have to amplify the signal as the 12D can only supply 1ma at 4.5v. I am using a random phase triac opto coupler moc3023 which needs 5ma.
You may not have used the 12d and 12e at the speeds I need. The amplifier is a npn transistor which may be too slow coming out of saturation.
I would point out to others on this forum that I would love to post a schematic but I can't because LTSpice uses .asc files which are not accepted on this forum.

I would suspect the interface between the decoder and the triac, but I can't comment further without the circuit diagram.

 

ok ht12d and ht12e info is here
https://www.holtek.com/productdetail/-/vg/2_12e
https://www.holtek.com/productdetail/-/vg/HT12D_F
you'd still need to post your schematic diagram