Reptile & Amphibian Forums

Is anyone familiar with utilizing the night time drop feature on the Johnson A419 thermostats? From what I can tell of the schematics and instructions, you should be able to incorporate what they call a "time clock." I've heard others mention toggle switches - but I'm looking for something automatic, like a standard household appliance timer. I doubt they're talking about the same thing.

Can anyone already using these thermostats successfully with the night time drop share how they have them set up? I already posted this in the caging forum, but thought I'd ask you folks as well.
Thanks,
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Joe Yakelis
HellFire Reptiles

This may not be much help but heres what I understand. The nightdrop feature that you are refering to is a second set of temp and offset settings in memory. The unit will switch to the second set of settings when you make a physical connection between the two pins. Not sure how you would achieve making it automatic? Im no expert when it comes to ac voltage but if you could wire a 120 volt relay to a timer that would work. When the timer applied voltage the contacts would close making continuity between the two pins,however you dont want to apply voltage to these two pins you just want them to have continuity.Honestly I think it would be cheaper to buy a Helix for $135.00 and the night drop cord for $30.00 I have a johnson controll thermostat and feel a basic switch wired to these two pins would be useful but not automatic. I do like the controller it has some cool functions. Make sure you set the fail mode to turn the unit off in the event of a sensor failure.These units have the ability to either turn the load on or off in the event of a sensor failure because they are comonly used for freezers. Hope this helps!
Bryan

Hey Bryan,

Thanks for the reply.

I like these thermostats for many of the same reasons you stated - but I was under the impression that employing a night time drop while using them would be a little easier at first glance. I use a couple of these thermostats in applications where a night time drop isn't required, and all fail modes are set to shut the unit down in case of sensor failure.

Since writing my original post, I've done some more research and Johnson does offer the time clock module they refer to in their schematics. I've found it listed, but without a price and not sure if it's available for resale, or for bulk wholesale only. I'm currently looking into it a bit further.

Depending on the price of the module and capabilities, I may be switching it out for another brand as you mentioned. I'm currently using the Johnson on a smaller rack that houses subadult animals. But it won't be long until they're adults, and figured I should start investigating this now. I really like these thermostats - alot - but may only be using them in applications where a night time drop doesn't need to be employed. Even the night drop feature on Big Apple's proportional model is extremely easy to incorporate compared to this. Thanks again for your input.

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Joe Yakelis
HellFire Reptiles

One thing you might consider when purchasing a new controller is make sure the sensor is replaceable.I have no first hand experience with the herpastat 2 thermostat but it has some really advanced features for the price. You can controll two different temps and timers and also has a add on feature that enables you to monitor your temps online via a usb connection. Sounds like something to research , They cost around $239.00 that does not include the sodtware. Good luck on your project !!!
Bryan