markelectro said:Torban
Cheers for that.I have taken a look and I will try and re-draw the complete circuit.
When I have worked it all out I will post it and then if you could pull it to bits cos I'm sure I won't get it right first time.
Regards Mark
markelectro said:Torban N all
Still tinkering with 555 timers!!!
Torban can't get a photo transistor circuit to trigger the 555.I will keep playing around in Livewire.
Mark
Torben said:Mark,
I found my schematic but it's a mess so I just did up a new one during lunch. Try the one attached below, but replace U1 with your laser and phototransistor--I just used the PC817A because it's essentially the same thing I couldn't find a spice model for the laser/phototransistor. This one will output a 0.517 second pulse every time the beam is broken, so if the beam break detector is across the very bottom of the pendulum swing you should get a half-second pulse once per second. I hope.
Q1 can be a garden-variety switching transistor like 2n3904, 2n2222, etc.
Hope this helps,
Torben
RODALCO said:The T&N seconds clock on the U tube video is ran from the tachogenerator.
I will make a shot of my 3/4 sekonds Bürks with the pendulum coils in synch, and put that on the other thread.
Hoeraah for digital photo and video technology.
Pommie said:Can I assume that the pic solution is no longer being considered?
Mike.
Pommie said:Can I assume that the pic solution is no longer being considered?
Mike.
Pommie said:Can I assume that the pic solution is no longer being considered?
Mike.
Pommie said:This is what I think you need as far as a circuit goes.
I would suggest a 32768Hz watch crystal as the code for PWM becomes fairly simple.
Anyone got a better suggestion for the input.
BTW, I'm currently playing here while my wife is watching soaps. Looks like it's the same the world over.
Mike.
markelectro said:Mike N all
The Parts list-
X1 PIC.16F628A
X1 Quad Half H driver- SN754410
X3 Resistors
X2 Capacitors
X1 Watch Crystal 32768HZ **broken link removed**
Right Hear goes!!
I tend to use -
https://www.maplin.co.uk/?DOY=6m8
for my electronics needs ,this is only due to the fact it is about 10 mins up the road from me.
I have searched their stocks and it seems that they cannot supply most of the items I require.
The Pic. 16F628A- They can supply a 16F628 but without the "A" Again due to my level of knowledge I don't really know how important the "A" is.
The Quad Half H Driver. SN754410-again they sell quad drivers but not this particular model.
The Watch Crystal 32768Hz They do actually sell
Resistors and Capacitors should not be a problem.
My questions are-
Can I use alternative quad drivers that Maplins stock?
Can I use the 16f628 PIC they have?
What value Resistors would I require for the circuit?
What value Capacitors would I require.
Can all these be purchased from one supplier in the uk.I will do a look around on Google!!!
I will first build on Breadboard and then may advance later once this is running.
I may bounce other questions as I look into this so I will apologise in advance for being percistant , like in the other examples we have I have to get to the bottom of this to get it up an running correctly.
I look forward to your replies and any advice you can give.
Kind regards Mark
The PIC16F628A is a later silicon revision. It uses newer process technologies and there are a few differences with the 628. Their importance really depends on your application. Supply voltage? Power consumption? Program memory size? EEPROM size? Price? (Availability, of course).markelectro said:The Pic. 16F628A- They can supply a 16F628 but without the "A" Again due to my level of knowledge I don't really know how important the "A" is.
Pommie said:Those all look ok. You should also order the parts for a 5V supply.
1 x 78L05
2 x 47uF electrolytic capacitors
4 x 0.1uF capacitors (extra for decoupling)
You may want to swap the 16F628 for a 16F88 as the later has a more flexible internal clock and it should be possible to develop a non crystal version with the 88. By timing the main clock and dividing it down in software, a very accurate 1 second pulse should be possible..
Pommie said:Having now read through the various threads and links, I think I may have misinterpreted what you require.
As I understand it, your clock is powered from 12V DC and outputs a 12V pulse every 30 seconds. Your slave clock requires a 24V AC signal every second.
I assumed that the slave required 24V DC for 0.5 seconds and the reverse voltage for the other 0.5 seconds.
I now think that it requires 24V @ 50Hz for 0.5 seconds and no voltage for the remaining 0.5 seconds.
Pommie said:Either way, the hardware will still work but the software will require some modification.
How can it do this every second?So both wires coming out of the slave will have-
approx 0.7 sec pulse length of 24v+ and approx 0.7 pulse length of -24v and then reversed next time around.
Pommie said:Mark,
I understand the contact and the changeover relay. The SN754410 does the same job as the changeover relay. What I am unsure of is your description of the voltages. From your description, the mechanism that would normally drive the slave would be powered from 48V DC and the changeover relay would convert it to ±24V - you need 48V in order to get -24 & +24 at the same time. I hope this is wrong and the mechanism is powered from 24V DC and what is actually output is 0V and +24V..
Pommie said:What I had assumed in the circuit diagram is that the 24V AC was the peak to peak voltage and could be derived from the 12V DC of the master. This appears to be wrong and means that the SN754410 will require a 24V supply instead of the 12V. It may be that the slave will work happily on 12V anyway - they probably allowed for long cable runs and consequent voltage drop.
Pommie said:One thing that would be useful would be a wiring diagram of a master/slave combination. Is there one any where on the web that you know of?
Pommie said:I'm also slightly confused about the timing.
You stated,
How can it do this every second?
I had assumed that it would be two 0.5 second periods.
Do you mean, 0.7s pulse of +24, 0.3s of no voltage, 0.7s of -24, 0.3s of no voltage.
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