Recent content by mminehan

Just want to provide an update.   I tested the breadboard prototype and after fixing a circuit assembly mistake the circuit worked perfectly.  A nice square wave on the output, and no bouncing counts. I left the LED in the circuit because the output voltage (3.2v) from pin 3 of 555 seems to be...

Thank you Larry, Robbin and CAI for your responses.   I have made up the circuit that Robbin posted a link to.  I have used breadboard like the link shows.  To test it I used a bench power supply set at 5V.  The LED lights up and stays lit while the switch is held closed.  And I managed to...

So I don't have access to a scope but did try a multimeter.  It seems the pulse is very wide with the contact closed maybe a 3rd of time during a cycle.  So it takes roughly 2 seconds for a 1 litre count with the relay closed for almost a second.   With the relay closed I measure around 4.9v at...

Thanks Larry, Robbin and CAI for taking the time to respond. Based on your replies it seems that a software debounce option is not viable. So I will have to experiment with a hardware solution (RC). I'll have to do some time constant maths to work out what size capacitor to use. From memory...

I am having some issues with a water meter connected to a WC8 (firmware v03.03.31).   The water meter uses a simple contact closure pulse relay.  I have connected it to TTL Input 1 on the WC8 and enabled TTL1 as counter.   This seems to be working except for what I think is some switch bouncing...

So....after a long time and many hours trying various options I have concluded that the only reliable way to get pH and ORP readings from a pool, with noise and ground loops, is to use an ISOLATED ph and ORP transmitter.   There are many options but most output 4-20mA for use in PLC controllers...

Hi Ross, The small board arrived last week and I have been doing some experimenting with mixed results. The board worked perfectly with the pH and ORP probes in the test solutions (isolated from the pool).  It only required some minor adjustment.  And I used the WebAmp to double the gain to get...

Ross, You are certainly going beyond what would be considered reasonable assistance. Thank you so much for your time and effort. It's nice to know that there are genuinely good people out there willing to help. Please allow me to provide you with some sort of remuneration for at least the...

Ross, Thanks again for you help. I'll go with option 2 seeing as I already have the WebAmp boards with the LM2902 installed. And I am sing one of the channels with a pressure sensor. Plus that way I can leave the regulator on the board too. Can you send me a PayPal invoice for the 4 channel...

Hi Ross, I'm keen to give the MCP op amp a try. But would need help with the schematic as my electronic skills are moderate (enough to turn a circuit diagram into a working circuit, but not skilled enough to design a circuit). I looked up the MCP6004 and ph electrodes and didn't find much. But...

Hi Ross, One of the smaller boards would be great. I would only need one of them. I can pay via PayPal. Also I have attached a picture of the regulator in the enclosure. I measured it and it protrudes about 8mm above the case. As you can see in the picture I trimmed the bottom of the heat...

Hi Ross and CAI Support,   Thanks for the advice regarding this.  Sorry I wasn't clear on the pH probe matter.  The confusion may have been the phidget boards I was using, but want to eliminate and so that I can connect the probes directly to the webamp.   I'm not sure I would be skilled enough...

Hi Ross, I'm not having much luck with the pH or ORP probes connected directly to the boards (with the mod suggested above).  I think the problem is they are very high impedance probes (50-500 megaohm) and have very low currents.  I can read the output directly from the probe with a digital...

Ross, Thanks for the prompt reply. I'm looking forward to getting the boards. I have a basic understanding of circuits. Great to read the WC8 can be powered from your board. I just PoE splitters to power the WC8 at present, and these can be set to 5, 9 or 12v...

Ross, I'm just a little confused about the power supply of the WC8 and the WebAmpV2 boards (having just purchased 2 with the regulator installed).  When you say "The V2 with regulator is the same board, but with TO-220 regulator and heatsink included. (Can run the webcontrol comfortably off a...