This is the first time I have ever needed help in my near 60 years in the trade, but perhaps as we grow older, we get more dafty.
I have in the past built an energy harvesting circuit to use on my Solar Panel Install. It is a fairly simple circuit using a single current loop on the incommer tail of my supply. When I export, the unit harvests the generated output minus power uasage into a hot water storage tank. My first unit has been running for near Five years with no problems. So, I thought I would knock up another unit. I built it and after checking everything many times plugged it in. Over the years I have always put the back of the finger on the chips to check temp, this time the AD633 was heating up too fast. I did the usual rechecked the circuit which was fine, bought another chip, popped it in and the same problem. I could not work out what was going wrong. It is same in every respect as my original circuit.
So I decided to buy one last one and put it into a simple test rig circuit. I used a breadboard and my bench power supply and reduced the running supply to +12 and -12dc and o volt gnd. I used a simple circuit on the Anologue Devices pdf, it is the squaring and freq doubling circuit, very simple, Ideal as a test. So armed with another chip I breadboarded the circuit, fed a 50 htz signal to pin 1+3 and grounded pin2+4 nd pin 6. I scoped the input and set it to 10v p to p sine wave in. My bench supply shows current and at swithch on current was 317ma. What I found was even with another new ad633 if I grounded pin 2 or pin4 then the chip drew max current. I left all connections open and just applied +12 volt and -12 volt , no current showing, I then grounded pin 6 and there was a 200 ma drain.
My simple question is"Am I going mad" There is the circuit below. This circuit is published, it is bound to work, so why are my chips burning out???????
This is the circuit I have built previously, so I know it works. It is a phase shift measurement circuit j2 is the current transformer looped over the incomming mains tail pin7 of the ad708 delivers a pulsed output when my solar panels are exporting and hence drives the output control of this unit.. Very simple. On the ad633 pin1 is a ac waveform and pin 3 provides a ref ac waveform from the mains when pin 7 goes neg, the o/p pulses drive the ad708. R10 and C10 together provide a dc monitoring voltage which allows trimming of the unit to stop using the harvesting unit when the generation is less then around 100watts .
So can anyone help with my dilema, what can I be doing wrong, perhaps I have bought a batch of duff chips, I just don't know, please dive in with any thoughts.
I have in the past built an energy harvesting circuit to use on my Solar Panel Install. It is a fairly simple circuit using a single current loop on the incommer tail of my supply. When I export, the unit harvests the generated output minus power uasage into a hot water storage tank. My first unit has been running for near Five years with no problems. So, I thought I would knock up another unit. I built it and after checking everything many times plugged it in. Over the years I have always put the back of the finger on the chips to check temp, this time the AD633 was heating up too fast. I did the usual rechecked the circuit which was fine, bought another chip, popped it in and the same problem. I could not work out what was going wrong. It is same in every respect as my original circuit.
So I decided to buy one last one and put it into a simple test rig circuit. I used a breadboard and my bench power supply and reduced the running supply to +12 and -12dc and o volt gnd. I used a simple circuit on the Anologue Devices pdf, it is the squaring and freq doubling circuit, very simple, Ideal as a test. So armed with another chip I breadboarded the circuit, fed a 50 htz signal to pin 1+3 and grounded pin2+4 nd pin 6. I scoped the input and set it to 10v p to p sine wave in. My bench supply shows current and at swithch on current was 317ma. What I found was even with another new ad633 if I grounded pin 2 or pin4 then the chip drew max current. I left all connections open and just applied +12 volt and -12 volt , no current showing, I then grounded pin 6 and there was a 200 ma drain.
My simple question is"Am I going mad" There is the circuit below. This circuit is published, it is bound to work, so why are my chips burning out???????
This is the circuit I have built previously, so I know it works. It is a phase shift measurement circuit j2 is the current transformer looped over the incomming mains tail pin7 of the ad708 delivers a pulsed output when my solar panels are exporting and hence drives the output control of this unit.. Very simple. On the ad633 pin1 is a ac waveform and pin 3 provides a ref ac waveform from the mains when pin 7 goes neg, the o/p pulses drive the ad708. R10 and C10 together provide a dc monitoring voltage which allows trimming of the unit to stop using the harvesting unit when the generation is less then around 100watts .
So can anyone help with my dilema, what can I be doing wrong, perhaps I have bought a batch of duff chips, I just don't know, please dive in with any thoughts.