Mid-Continent Instruments TRUE BLUE POWER TC120 Technical Document

Revision H April 13, 2021

1 Manual Number 9018558 • Revision H, April 13, 2021
FOREWORD
This manual provides information intended for use by persons who, in accordance with current
regulatory requirements, are qualified to install this equipment. If further information is required,
please contact:
True Blue Power
c/o Mid-Continent Instrument Co., Inc.
Attn: Customer Service Dept.
9400 E. 34th St. N.
Wichita, KS 67226 USA
Phone [phone]
Fax [phone]
www.truebluepowerusa.com
www.mcico.com
We welcome your comments concerning this manual. Although every effort has been made to
keep it free of errors, some may occur. When reporting a specific problem, please describe it
briefly and include the manual part number, the paragraph/figure/table number and the page
number. Send your comments to:
True Blue Power
c/o Mid-Continent Instrument Co., Inc.
Attn: Technical Publications
9400 E. 34
th
St. N.
Wichita, KS 67226 USA
Phone [phone]
Fax [phone]
© Copyright 2016
Mid-Continent Instrument Co., Inc.
Download the current
version of this
installation manual
using your
smartphone or tablet.

2 Manual Number 9018558 • Revision H, April 13, 2021
TABLE OF CONTENTS
SECTION 1GENERAL DESCRIPTION 4
1.1INTRODUCTION 4
1.2TECHNICAL SPECIFICATIONS 5
SECTION 2PRE-INSTALLATION CONSIDERATIONS 6
2.1COOLING 6
2.2EQUIPMENT LOCATION 6
2.3ROUTING OF CABLES 6
2.4LIMITATIONS 6
2.5MODIFICATION 7
SECTION 3INSTALLATION 8
3.1GENERAL INFORMATION 8
3.2UNPACKING AND INSPECTING EQUIPMENT 8
3.3CABLE HARNESS 8
3.4MOUNTING 11
3.5INSTALLATION CAUTION 11
3.6INSTALLATION COMPLETION 11
SECTION 4OPERATION 12
4.1ELECTRICAL PERFORMANCE 12
4.2TC120 AVILABLE CURRENT OVER THE OUTPUT VOLTAGE RANGE 12
4.3PROTECTIVE FEATURES 13
SECTION 5CONFORMANCE 16
5.1INSTRUCTIONS FOR CONTINUED AIRWORTHINESS 16
5.2ENVIRONMENTAL QUALIFICATION STATEMENT 16

3 Manual Number 9018558 • Revision H, April 13, 2021
REVISION HISTORY
Rev Date Detail Approved
A 02/10/2016 Initial release SHO
B 03/04/2016 Updated EQF in Section 5, corrected input voltage range,
added note to Section 2.4. BAW
C 03/15/2016 Add -2 version. BAW
D 05/27/2016 Updated wiring drawings in Section 3. VAA
E 02/10/2016 Updated Section 4.2.1. KJW
F 05/07/2020 Updated style and brand to meet Marketing and
Engineering guidelines. DLR
G 10/21/2020 Updated weight. MEK
H 4/13/2021
Updated Section 4 – provided additional clarification in the
operation section; correct graph info; added new graph to
illustrate power range. Section 5 corrected typo
DLR

4 Manual Number 9018558 • Revision H, April 13, 2021
SECTION 1 GENERAL DESCRIPTION
1.1 INTRODUCTION
The model TC120 DC/DC Power Converter is a lightweight power converter that translates a direct
current (DC) input of 28 volts to an adjustable 5 to 18 volt direct current (DC) output.
The input operating voltage (24–32VDC) makes the TC120 suitable for nearly any common
general, business, or commercial aviation application and provides an adjustable DC output
voltage of 5 to 18VDC. The unit is rated for a nominal output of 120 watts to power avionics,
instrumentation, personal charging, lighting, and many other applications. The TC120 DC/DC
Converter is FAA certified to TSO-C71 and tested to rigorous environmental standards and levels
of RTCA DO-160G. The small size and light weight in conjunction with its installation flexibility
(inside or outside the pressure vessel) make it an ideal choice for aircraft power needs while
reducing the challenges associated with other similar products.
Highlighted features include short circuit protection, overload capability, low input voltage shut-
down, temperature monitoring, reverse polarity protection, a self-resettable over-temperature
disable and an optional remote enable (on/off) feature.
The TC120 DC/DC converter has a robust Military-rated circular connector and a rugged aluminum
case which dissipates heat and provides excellent mechanical strength. It is engineered to require
no external cooling and contains no internal fans or cooling methods, which saves energy, reduces
weight and allows more flexible installation locations. At only 11.0 oz (312 g), it is lighter and
smaller than any other certified solution in the aviation market today.

5 Manual Number 9018558 • Revision H, April 13, 2021
1.2 TECHNICAL SPECIFICATIONS
Electrical Attributes
Input Voltage Rated 28VDC nominal, Operating 24 – 32VDC
Input Current (full load) 5 amps max at nominal input voltage
Output Voltage 5 – 18VDC adjustable
Output Power 120 watts nominal
Efficiency 95% nominal
Table 1.1
Physical Attributes
Weight 11.0 oz (312g)
Dimensions
(not including connector mate)
2.75 inches long x 3.75 inches wide x 1.29
inches high
(69.9 mm long x 95.3 mm wide x 32.8 mm high)
Mating Connector Kit MCIA P/N 9018651
Mounting Base mount – orientation not critical
Table 1.2
Qualifications
Certification FAA TSO-C71
Environmental Qualification RTCA DO-160G Environmental Category;
See Section 5.2
Altitude -15,000 feet to +55,000 feet
Temperature -55°C to +70°C (-67°F to +158°F)
Table 1.3

6 Manual Number 9018558 • Revision H, April 13, 2021
SECTION 2 PRE-INSTALLATION CONSIDERATIONS
2.1 COOLING
The TC120 product does not require external cooling or contain internal active cooling. Cooling of
the unit occurs exclusively through passive conduction through the base or radiated cooling across
the metal case. Additional cooling can be realized through convection (exposure to free moving air)
or conduction (mounting to a thermally conductive metal surface). These methods are not required
to achieve rated performance but can help prevent potential overheating and extend life when the
unit is operated at full power or during overload conditions. Specifically, mounting the unit to a
metal surface is preferred, but not required.
2.2 EQUIPMENT LOCATION
The TC120 is designed for mounting flexibility, allowing for installation inside or outside the
pressure vessel with no requirement for temperature control. In addition to altitude and
temperature resistance, the unit is also designed to withstand high levels of condensing humidity.
However, installation locations where the unit could be subject to standing or direct water exposure
should be avoided. The unit can be mounted in any orientation. Clearance should be provided for
the mating connector and may require as much as five inches past the unit connector to allow for
back shell access to the connector.
2.3 ROUTING OF CABLES
The wires and cable bundle associated with the unit are heavy gauge wire and carry significant
power. Be aware of routing cables near other electronics or with other wire bundles that may be
susceptible to high energy flow.
Avoid sharp bends in cabling and routing near aircraft control cables. Also avoid proximity and
contact with aircraft structures, avionics equipment, or other obstructions that could chafe wires
during flight and cause undesirable effects.
2.4 LIMITATIONS
The conditions and tests for TSO approval of this article are minimum performance standards.
Those installing this article, on or in a specific type or class of aircraft, must determine that the
aircraft installation conditions are within the TSO standards. TSO articles must receive additional
installation approval prior to being operated on each aircraft. The article may be installed only
according to 14 CFR Part 43 or the applicable airworthiness requirements.

7 Manual Number 9018558 • Revision H, April 13, 2021
2.5 MODIFICATION
This product has a nameplate that identifies the manufacturer, part number, description,
certification(s) and technical specifications of the unit. It also includes the “MOD” or modification
number representing notable changes in the hardware design of the unit.
Modification (MOD) 0 is the initial release of the product and is identified on the nameplate by the
lack of marking on the MOD numbers 1 through 9 (i.e. 1-9 are visible). All subsequent
modifications are identified on the nameplate by the marking/blacking out of that particular MOD
number (i.e. for MOD 1, the number 1 is not visible and 2-9 are visible - see Figure 2.1 for
examples). MODs do not have to be sequentially inclusive and may be applied independent of
each other.
For additional details regarding specific changes associated with each MOD status refer to the
product published Service Bulletins at www.truebluepowerusa.com.
Figure 2.1
Nameplate and MOD Status Example
MOD 0
MOD 1
MOD 1
& MOD 2

8 Manual Number 9018558 • Revision H, April 13, 2021
SECTION 3 INSTALLATION
3.1 GENERAL INFORMATION
This section contains interconnect diagrams, mounting dimensions and other information
pertaining to the installation of the TC120 DC/DC Converter. After installation of cabling and before
installation of the equipment, ensure that power is applied only to the pins specified in the
interconnect diagram.
The following two versions of the unit are available. See section 4.2.1 for additional details of the
remote enable (on/off) feature and installation details within section 3.
Part Number Remote On/Off
6430120-1 No (output always enabled)
6430120-2 Yes (enable signal required)
3.2 UNPACKING AND INSPECTING EQUIPMENT
When unpacking this equipment, make a visual inspection for evidence of any damage that may
have incurred during shipment. The following parts should be included:
A. DC/DC Converter P/N 6430120-( )
B. Connector Kit P/N 9018651
i. Mating Connector
ii. Strain Relief
C. Installation Manual P/N 9018558
Equipment not provided:
A. Mounting Hardware four 6-32 x 1” (min) pan head screws
#6 lock washers (optional)
B. Cable Harness Wire See Section 3.3 for specifications
3.3 CABLE HARNESS
Construct the cable harness with regards to the instructions below, and using Figures 3.3 – 3.5,
and Wiring Diagram of Table 3.3.
Refer to Section 2: Pre-Installation Considerations in regards to routing precautions.
Wire Gauge Selection
Use of PTFE, ETFE, TFE, Teflon, or Tefzel insulated wire is recommended for aircraft use.
Use the following wire gauges for each of the pins in the connector:
Pins A and B – 18 or 16 AWG stranded or solid
Pins C and D – 16 AWG stranded or solid
Pin E – 24 AWG stranded or solid

9 Manual Number 9018558 • Revision H, April 13, 2021
Pin Assignment Information
DC Input – (24-32 VDC). Connect pin A to the aircraft positive 28 VDC bus
(7.5 amp circuit breaker recommended)
DC Return – Connect pin B to input power return or aircraft ground. Equivalent to pin D
DC Output – Connect pin C as the positive output voltage (adjustable)
DC Return – Connect pin D to output return or aircraft ground. Equivalent to pin B
Enable – 6430120-1: pin E to remain open/unconnected
6430120-2: pin E to be grounded to enable power output
(via switch or other means. See section 4.2.1 and figure 3.3 for related details)
Figure 3.1 Table 3.1
Pinout View of Unit Connector Connector Pinout
Harness Verification
With the TC120 DC/DC Power Converter disconnected, activate the aircraft power bus that
supplies the unit and use a multi-meter to measure and verify the power, ground, and
enable voltages on the appropriate pins within the mating harness.
Output voltage Adjustment
The output voltage can be set to any value between 5 and 18VDC.
NOTE: The default output voltage is initially set to approximately 13.8V at the factory.
The output voltage may be adjusted while the TC120 DC/DC Power Converter is
connected to the mating harness and aircraft power, but disconnected from the output load.
Use a multi-meter at the load end of the harness to measure output voltage.
The adjustment trimmer may be accessed by removing the 4-40 screw near the label as
shown in Figure 3.4. After removing the screw, a flat blade screwdriver (2mm) will fit into
the hole and the trimmer. Turn the trimmer carefully either clockwise to increase voltage or
counter-clockwise to decrease voltage. Replace the 4-40 screw after adjustment is
complete.
Connector Pinout
A DC Input
B DC Return
C DC Output
D DC Return
E Enable
A
D
B
E
C

10 Manual Number 9018558 • Revision H, April 13, 2021
E
D
DC OUTPUTC
DC RETURN
B
ADC INPUT
TC120
5-18V OUTPUT
ADJUSTMENT TRIMMER
DC RETURN
6430120-1
(NOT CONNECTED)
Figure 3.2: Typical 6430120-1 Aircraft Wiring Installation – Constant On
A
B
C
ON/OFF
ON
OFF
ENABLE
D
DC INPUT
TC120
E
5-18 V OUTPUT
ADJUSTMENT
TRIMMER
DC OUTPUT
DC RETURN
DC RETURN
6430120-2
Figure 3.3: Typical 6430120-2 Aircraft Wiring Installation – Remote On/Off

11 Manual Number 9018558 • Revision H, April 13, 2021
3.4 MOUNTING
Refer to Section 2: Pre-Installation Considerations in regards to equipment location.
The TC120 DC/DC Converter is designed for base mounting only. Four 6-32 mounting holes
should be provided in the aircraft in accordance with Figure 3.6. Secure the unit with four 6-32 pan
head screws, or equivalent. A lock washer under the head of each screw is recommended.
3.75
1.29
3.38
2.75
2.40
0.57 4X Ø0.15 Mounting Holes
for #6-32 X 1.0" (min)
Connector per
MS3102A-14S-5P
Output voltage
adjustment
Figure 3.4
TC120 DC/DC Converter Outline Drawing
3.5 INSTALLATION CAUTION
Under no circumstances should the output of the Converter to be connected to another power
output source or damage will occur to the unit or the connected power source.
3.6 INSTALLATION COMPLETION
Prior to operating the unit in the aircraft, it is recommended to verify the output and functionality of
the unit. In order to prevent accidental damage to other systems, it is best not to attach the output
to other equipment or power busses prior to verification. Verify the output of the unit at the
terminating end of the cable with a multi-meter to ensure proper voltage and polarity. Once
verified, installation can be completed and functionality of the remote on/off feature (if used) should
be checked.

12 Manual Number 9018558 • Revision H, April 13, 2021
SECTION 4 OPERATION
4.1 ELECTRICAL PERFORMANCE
The TC120 DC/DC Converter is designed as a high-efficiency non-isolated, buck topology, solid-
state switch-mode power supply. The unit converts a DC voltage input to a user-selected
regulated 5 to 18 VDC output. The Pulse-Width-Modulation (PWM) circuits utilize current-mode
control technology. The current-mode control operates at high frequency and pulse-by-pulse
protects the internal power devices from excessive current.
4.2 TC120 AVILABLE CURRENT OVER THE OUTPUT VOLTAGE RANGE
The TC120 continuous rated output current, and thus power, is a function of the user-selected
output voltage. The TC120 is rated for 120 Watts. If the selected output voltage is lower than 9
VDC, then the continuous rated output current is limited by the typical maximum current of the MIL
510514-5P connector and mating harness connector. See Figure 4.1 for maximum continuous and
temporary output current for a given voltage output.
The left side of Figure 4.1 shows the continuous current region of the TC120. The area to the right
of the Power Limit and Connector Limit show the temporary current capability of the TC120. The
continuous rated current can be exceeded for short periods of time (up to 2 hours) to
accommodate surge conditions and fault conditions. This also allows the TC120 the capability to
trip slow-acting thermal circuit breakers under fault and short-circuit conditions without
degradation.
If an installation if the TC120 is expected to supply high currents, then the allowable voltage drop
from wire length between the TC120 and the load must be taken into account. The current rating
on connectors is also dependent upon wire size. The larger the wire the more heat that is pulled
from the pins and the higher the current the connector can withstand.

13 Manual Number 9018558 • Revision H, April 13, 2021
Figure 4.1
TC120 Continuous and Temporary Output Current Limits and Output Voltage
4.3 PROTECTIVE FEATURES
Remote On/Off
A version of the TC120 DC/DC Converter (6430120-2) incorporates a remote ON/OFF
feature that allows the user to enable or disable the output of the unit remotely. By
providing a ground to the appropriate pin, the user can enable the output of the unit via a
remote mounted switch. (See Figure 3.3)
Input Voltage Range
The nameplate rating of the TC120 and qualification testing is 22 to 34 VDC. However the
TC120 can temporarily operate at much lower voltages for start-up and emergency
conditions. See Figure 4.2

14 Manual Number 9018558 • Revision H, April 13, 2021
Figure 4.2
TC120 Input Voltage vs Output Voltage Range
The Temporary Operating Range represents a voltage range where extensive performance
and qualification measurements have not been made other than for DO-160 Section 16 at
18VDC. If you require a TC120 fully qualified for input operation below 22 VDC contact
Mid-Continent Sales.
In the Temporary Operating Range of Figure 4.2, the TC120 cannot boost the input voltage
to produce a higher output voltage. As an example, if the output voltage is set for 18 Volts
and the input voltage falls below 19 Volts, the output voltage will begin to fall-off and will be
about 1 Volt less than the input voltage.
Maximum Input Voltage
If the input voltage to the TC120 exceeds 34VDC, the unit senses an over-voltage at the
input and disables the output. The TC120 resumes normal operation when the input
voltage drops below 34VDC.

15 Manual Number 9018558 • Revision H, April 13, 2021
Output Voltage Range
In Table 1.2 the adjustable Output Voltage range of the TC120 is 5 to 18VDC. Each
individual TC120 is tested to this range. The actual adjustment range of the trimmer is
typically 4.3 to 18.4 VDC. If you require an adjustment range other than the specified 5 to
18VDC range contact Mid-Continent Sales.
Over-Temperature
The TC120 DC/DC converter uses a high-efficiency conversion process. The TC120 at
maximum continuous power will have a case temperature typically 20C over ambient. For
additional protection the TC120 has an internal temperature sense device that continually
provides monitoring and feedback to the control circuits. When the unit senses an internal
condition that exceeds maximum temperature ratings the output is disabled. The converter
will continue to remain shut-down until the temperature returns to within acceptable limits.
This over temperature reset occurs automatically without external intervention required.
Short Circuit
The TC120 DC/DC converter has a maximum output current. As the load current increases
beyond the maximum continuous rating a point will be reached where the TC120 output
voltage begins to drop. At a full short-circuit the input current to the TC120 is low but the
output current is approximately 22.5 Amps (See Figure 4.1). The TC120 can withstand
continuous short-circuit operation without damage.
If it is undesirable in your installation for the wiring to be subjected to high currents in a
short-circuit fault condition a circuit breaker on the TC120 output should be used.

16 Manual Number 9018558 • Revision H, April 13, 2021
SECTION 5 CONFORMANCE
5.1 INSTRUCTIONS FOR CONTINUED AIRWORTHINESS
No periodic scheduled maintenance or calibration is necessary for continued airworthiness of the
TC120 DC/DC Converter. If the unit fails to perform to specifications, the unit must be removed
and serviced by Mid-Continent Instruments and Avionics or their authorized designee.
5.2 ENVIRONMENTAL QUALIFICATION STATEMENT
MODEL NUMBER: TC120 PART NUMBER: 6430120-( )
DESCRIPTION: DC/DC Converter CERTIFICATION: FAA TSO-C71
MANUFACTURER: True Blue Power, a division of Mid-Continent Instrument Co., Inc.
ADDRESS: 9400 E. 34th St. North, Wichita, KS 67226, USA.
SPECIFICATION: Test Specification (TS) 627 Test Data Sheet (TDS) 627
STANDARD: RTCA DO-160, Rev G, dated 12/08/10
CONDITIONS SECTION DESCRIPTION OF TEST
Temperature and Altitude 4 Category F2
Temperature Variation 5 Category S2
Humidity 6 Category B
Operational Shock and Crash Safety 7 Category B
Vibration 8 Fixed Wing: Category R; Curve C, C1
Rotorcraft: Category U, Curve G
Explosion 9 Category X
Waterproofness 10 Category X
Fluids 11 Category X
Sand and Dust 12 Category X
Fungus 13 Category F
Salt Fog 14 Category X
Magnetic Effect 15 Category Z
Power Input 16 Category B(XX)
Voltage Spike 17 Category B
Audio Frequency Conducted Susceptibility 18 Category R
Induced Signal Susceptibility 19 Category X
Radio Frequency Susceptibility 20 Category X
Emission of Radio Frequency Energy 21 Category M
Lightning Induced Transient Susceptibility 22 Category X
Lightning Direct Effects 23 Category X
Icing 24 Category X
ESD 25 Category A
Fire, Flammability 26 Category X
REMARKS: