Please help me find values for this simple circuit

Well, it would be useful to know (measure directly or indirectly) the input resistance of the module (and maybe if it is relatively constant WRT voltage)... Then one could use Ohms law, etc to calculate voltages using a 28V supply and then do another set of calculations with the persumed 24V supply. Most likely those resistors are 10 percent tolerance, and the ranges (a

For 24V: R4= 10k, R5= 9.66k, and R6= 2.33k.

What is non-standard about 24/28 volt batteries? Everything from Cessna to Boeing uses this as the primary dc battery voltage.

Jim

-- "Dream as if you'll live forever. Live as if you'll die today."

--James Dean

I meant to say I need the values of:

voltage a voltage b voltage c voltage d voltage e voltage f

based on using a 24V not a 28V source.

redraw the circuit for each case, then apply krichorff's laws and basic algebra.

any further questions belong in sci.electronics.basics

Bye. Jasen

The ratio of Vmodule/Vbatt runs at 1/11, 1/8, and 1/6 for the respective circuit conditions. Beyond this it is impossible to say without knowing the ratiometric extents of Vbatt and the resistors relative to their nominal values. Once *you* determine these parameters, simply sum and difference those errors from 1 and multiply by Vbatt to get your bounds.

In practice, they are used interchangeably to mean the same thing. 24 volts is comparable to an automotive "at rest" 12 volt system and 28 volts is the "under charge" 14 volt automotive value. If you had ever worked in the aviation environment you would know that.

Jim

-- "Dream as if you'll live forever. Live as if you'll die today."

--James Dean

That's right, indeed, that's what I'm asking for in my post.

I used to have a program called Electronics Workbench. When I had a simple circuit like this, I would let the program use whatever its default values were for everything, I would wire the circuit, set the resistor and voltage values, and click "Run" with the switch open (Normal), and then closed (Alarm), and then in the supervisory alarm failure position (the 6.8k disconnected). The results were all I needed for my purposes.

This is the same situation. I need to know what Va, Vb, Vc, Vd, Ve, Vf would be for this circuit. Doesn't anyone out there have something like Electronics Workbench they can plug in these values, and post of screen-shot of the circuit in the Normal, Alarm, and Supervisory Alarm conditions? Takes about 2 minutes. Do they still make Electronics Workbench? Is there a simple, cheap, easy, basic R/l/C circuit analysis shareware program out there I can download?

I know how to do KVL, I'd just rather not dive into it that way, that's like doing long division instead of using a calculator.

Well, i do know that, but the batteries are labelled and specified at

Do your own homework; get out the pencil and paper and do the

Success!

I found a pretty good free circuit modeling program called SwitcherCAD/ LTspice by Linear Technologies. It displays voltage and current readings wherever you point the probe.

Old fashioned military IC/SM alarm switchboard panels are required to be hooked up to various types (liquid level, pressure, temperature, whatever) of level switches that have a built-in 6.8k resistor, for supervisory circuit monitoring (current sensing). This circuit replaces the IC/SM panel, and it backwards compatible with the 6.8k switch combo. I want to use a 0 to 10 VDC analog input module, so I chose these R1 R2 R3 values to keep my measurement across R1 in that range. I don't want the 24VDC supply's current draw to be under 3mA. This circuit accomplishes this. It's just a simple voltage divider, of course.