DEVELOPMENT, MANUFACTURING AND SUPPLY OF INSTRUMENTATION
48
11.5 Design and function
Convenient and user-friendly control and indication units with explanations, the elementary
control algorithm backed by automation (“intuitive interface”), several protection levels from
emergency modes, all these things help any untrained operator to master the device within the
shortest period.
The automatic adjustment allows to generate the specific signal current at the wide range of
the load resistance. The transmitter can be connected to the load directly via connecting wires
(“contact” way of connection) or by “non-contact” (induction) method with the use of the internal
transmitting antenna or with the extra accessories involved, e.g. external transmitting antenna or
induction “clamp”.
The circuit solution of the power amplifier is implemented in the unique upgrade of the CLASS
D technology and provide the highest degree of efficiency among all the known circuit design
concepts for the power amplifiers. Thanks to the above-mentioned the relatively long “life cycle”
in the autonomous mode at such a high initial maximum output power is achieved despite the light
weight and small size of the device.
The values of the output current set by the program at the automatic adjustment with the load of
“occasional” resistance are optimum judge from the sensitivity of the majority of cable avoidance
tools and are equal to 0.2A at “low” frequencies 512Hz «0.5» and 1024Hz «1.0» and 0.1A at “high”
frequencies 8192Hz «8.2» and 32768Hz «33». During the automatic adjustment load voltage
incrementally increase until the moment when the values of the absorbed current and load current
will not exceed the figures set by the program. If pre-set load current value is not achieved due
to the high load resistance then maximum possible output voltage is defined. Upon completion
(or interruption by START/ STOP «
» buttons) of the automatic adjustment process, the manual
control over the voltage (current, power) is available via buttons LESS/ MORE« ».
Under power supply voltage decrease during oscillation (e.g., batteries self-discharge) the
signal output voltage is lowering proportionally (incrementally) (and consequently absorbed
power) as the supply source “energy potential” reduce. This program system extends batteries’
“life cycle” considerably. Therefore while searching there is no premature “path loss” and the
decrease of signal strength is offset by the wide range of options for the manual or automatic
adjustment of the sensitivity of receivers made by “TECHNO-AC”.
WARNING! ENERGY SAVING!
All operations with output voltage (current, power) under connected load lead to the
changes of the energy consumption (and consequently “life cycle” of the autonomous
power supply). Watch the indicators of the power supply voltage “U” and absorbed
current “I” in the “electrical power supply field” so that the time is enough to perform
utility locating. In order to save energy operate the device at the minimum sufficient load
power. Always use “economy” pulse mode “Pu” when applicable. The operation breaks
help to partially restore the capacity. Therefore “net” operating time with interruptions is
always more than time of continuous operation all other conditions being equal. The fall of
environment temperature at the autonomous battery power supply has an adverse effect
on the “life cycle” of the power supply set (especially crucial at sub-zero temperatures).
Always have a backup set of batteries.
NOTE
While changing batteries use only all 8 elements of “type C” produced by the same company,
from same series and condition (all 8 cells are always operable or inoperable altogether).
ALKALINE 1,5V batteries are recommended.
Zinc-carbon (1.5V) batteries can be used only in case of “emergency” (at the lowest possible
output power and preferably in the “economy” pulse mode “Pu”) because of the extremely low
load capability.
Summary of Contents for AP-019.1
Page 1: ......
