User guide

P/N: 021-00154, Rev. A.6 - updated for V4.7 Tools Page | 149
Appendix C Troubleshooting Systems
Basic Electronics Theory and DVC System Troubleshooting
Electronics is not nearly as scary as a high-pressure hydraulic leak and is much less messy. With basic
understanding and simple tools, electronics can be applied and trouble shot easily and successfully.
All of HCT's products involve electronics and HCT’s goal is to make it easy for you to quickly get them to work in
your systems. To make you more comfortable with integrating electronic controls with fluid power we have
provided you with a quick introduction to basic electronics below and a means to tell if it is working.
Basic Electronics Introduction
The b
asic medium of exchange is an electron. When a whole bunch of electrons get together with a destination
in mind it is called voltage like in a battery. Voltage is the pressure that causes the electrons to want to flow.
When the electrons move, it is called current. Current makes things happen. It is analogous to "fluid" flow.
Resistance is the restriction to current's flow in a wire. More voltage (i.e. pressure) will result in more current
flow through a wire for a given resistance. Flowing current causes magnetic fields to surround the wire
conducting the current. When current flows through a coil surrounding a magnetic material (i.e. spool) the
magnetic fields are concentrated and produce a Magnetic force. This Magnetic force is proportional to the
current flow, number of coil turns and the magnetic material surrounded by the coil. The produced magnetic
force can be used to cause valve spool and electric motor movement. Just as forcing fluid through a restriction
generates heat, forcing current through resistance also generates heat. The heat is measured in wattage.
Inductance is the property of a coil to resist changes in current flow and therefore to maintain the generated
magnetic force. More inductance will cause more "inertia". Capacitance is the property of a capacitor to resist
changes in voltage across its two terminals. More capacitance will cause more "shock absorbing" action to
remove voltage (pressure) spikes. Now that the basic concepts have been introduced we present to you the
basic formulas of how the above terms are calculated. No formulas involving magnetism, inductance or
capacitance are presented as they usually involve calculus, which is seldom are useful to consumers of
electronics and understanding that level of detail is left to us.
Useful formulas
W = watts, V = volts, I = amps, R = ohms
V = I * R
V = W / I
V = Square Root (W * R)
W = V * I
W = I * I * R
W = V * V / R
I = V / R
I = W / V
I = Square Root (W / R)
R = V / I
R = (V * V) / W
R = W / (I * I)
How to hook it up
Current insists on being able to flow back to where it started from be it the negative terminal of a battery or the
ground and thus the name circuit. Current has to return to the tank or you run out and no power is transferred.
You must have two wires hooked up to work. The first wire usually connects the circuit input to the more positive
voltage coming out of the power supply or battery which is often referred to as Power, Positive, High or Plus.
The second wire connects the output of the circuit to the more negative voltage commonly referred to as
Ground, Return, Common, Negative, Low or Minus. This current return second wire of a circuit can often be
connected directly to the chassis of the system. The chassis ultimately will connect to the negative terminal of a
battery or ground. In this case care must be exercised that there are no cracks or joints that cause unnoticed