Last updated on July 10th, 2018 at 09:20 am
Variable Power Supply also is known as Bench Power Supply is one among the obligatory devices in Electrical & Electronics Engineering Workbench. It provides voltage and current to all the elements present in a Circuit.
Technically, it is an active device i.e. producing Energy in the form of voltage and current.
The main concept of a Power Supply is to convert Alternating Current (AC) into an adjustable Direct Current (DC).
Some power supplies have a feature to adjust either current or voltage and sometimes both current and voltage.
The following document gives an in-depth essence of TEKPOWER TP3005T Variable DC Power supply.
TECHNICAL COMPARISON BETWEEN VARIOUS MODELS OF TEKPOWER:
A brief overview of the various models of Tekpower Power Supply Models,
|Voltage||(0 – 30) V||(0 – 30) V||(0 – 50) V|
|Current||(0 – 3) A||(0 – 5) A||(0 – 3) A|
TEKPOWER TP3005T DC Power supply is a Linear Regulated variant which means that the user can have a constant control over the current or voltage that is being adjusted.
The product’s output voltage and current rating could be easily decoded from the model number i.e.
TP3005T => TP / 30 / 05 / T
TP → Tekpower 30 → 30 Volts, DC Voltage
05 → 5 Amperes, DC Current
It is Obvious that this power supply has rated output DC voltage range of (0 – 30) Volts and current rating of (0 – 5) Amperes.
Both the parameters, current as well as voltage are adjustable with the help of two separate control knobs present on the front panel of the power supply.
Altogether, TEKPOWER TP3005T is a Constant Current (CC), Constant Voltage (CV) Linear Regulated DC power supply completely. It is completely made in China.
The Front Panel of the TEKPOWER TP3005T starts with a dual row of 4 seven segment numerical displays in each row, displays the output values up to a 4 digit range. The onboard LED indicators provide status indication about,
- Over Current Protection (OCP): When this feature is enabled, the OCP LED is ON and if disabled it goes OFF. OCP can be activated by holding down the Voltage control knob for a moment and adjust it to set it ON and OFF.
- Constant Current (CC): LED goes ON when a constant current is flowing through the test device. The output voltage changes with the resistance of the load, maintaining the current at a constant level.
- Constant Voltage (CV): LED goes ON when a constant voltage is flowing through the test device. The output current changes with the resistance of the load, maintaining the voltage at a constant level.
- Lock: When this feature is enabled, the Lock LED goes ON. Also, the voltage and current control knobs remain ineffective during adjustment. Returns back to original state by disabling lock feature. Lock Feature can be activated by holding the Current Control knob for about 3 seconds and also disabled by repeating the same procedure.
The Display Panel is followed by a set of control knobs – voltage and current adjustment.
Technically, those are two solid clickable rotary encoder knobs with small detents (while turning) capable of finer adjustments.
By pressing and holding the current and voltage knobs for a moment will enable lock and OCP feature respectively.
Pressing the current knob or the voltage knob once for a shorter time duration makes the power supply to enter into Edit Mode/Set Mode where the desired value is set in increments or decrements by varying the knob.
Repeated pressing of the knobs will shift the location of the digits place from the previous one.
When unadjusted in Edit mode, it normally goes into Display Mode — A niche way in setting the voltage and current values on the power supply.
This kind of click and hold mechanism avoids errors and also instantaneous power spikes during accidental operations.
The control knobs are followed by a clickable power ON/OFF switch and a Banana Connector of 3 terminals for output voltage and current – Positive Terminal (+), Ground and Negative Supply (-)
The Core part of TEKPOWER TP3005T DC Power supply is of two types with the center tapped linear transformer as a reference.
A set of transformer taps are connected to the main electric power circuit board, which is attached to a cooling fan via a heat sink.
The power board PCB consists of Bridge Rectifier, Pass Transistor, and Filtering Capacitors.
A temperature sensor detects the overheat dissipation and runs the cooling fan automatically than a certain threshold level.
Another set of transformer taps are connected to the front panel electronic circuit board.
PIC16F887 Microcontroller acts a heart of the electronic circuit board without inputs and outputs.
It is an 8 bit, 40 pins with 10 pins on each side and Surface Mount Type (SMT) manufactured by Microchip Technology and it is a single chip Integrated Circuit (IC) for display and precision control.
A Brief about the Key Features:
- Resolution of TP3005T is 10mV/1mA, which defines the level of precision in generating the output voltage and current.
- When measured in parallel with a Multimeter, the measurements are so accurate and relative to the power supply.
- Microprocessor’s non-volatile memory holds the last varied value before power off and retains it during power on.
- Reverse Current Protection Diode to avoid Reverse Polarity during operation, power supply automatically shuts down.
- Suitable for School and College Labs, Electronic Enthusiasts, Do It Yourself (DIY) Hobby Project Makers, Tinkerers and Industrial Applications.
- Dual Safety Relay’s to trip safely between the voltage ranges offers high reliability and grounding connection is provided as per industry standards.
IS TEKPOWER TP3005T RELIABLE?
The Tekpower TP3005T lacks external connectivity and operates only in 110 V / 60 Hz.
It will be a bottleneck for those people who live in a region where the domestic power supply rating is not 110 V / 60 Hz. But,
the appreciable thing about the power supply is the resolution and precision.
It will definitely create a curiosity in the mind of a TP3005T user in terms of internal wiring,
the active and passive electronic components involved,
the effective design of the Power Supply Printed Circuit Board etc.,
The Manufacturer has given a considerable priority to Over Current Protection (OCP Feature) and Over Heat Protection which is measured by a temperature sensor.
Also, the design and placement of the rectifier circuit components are pretty unique as the back surface of the rectifier IC, pass transistor and also the cooling fan are combined together on the surface of the heat sink whose surface area is equal to the exhaust cooling fan. The intelligent switching on and off of the exhaust cooling fan happens at two crucial conditions,
- When the Edit mode current value is greater than 1 Amperes
- When the Power Supply gets hot with continuous usage.
The Temperature sensor/temperature detector is interfaced and programmed perfectly with Microchip’s PIC16F887 in such a way that it has automatic speed control i.e., the speed of the cooling fan varies with the cabinet temperature and runs without any variation in load.
Also, the implementation of storage to hold the lastly stored values after power supply shut down makes it easier to restore the values of voltages and currents when there is a case of sudden power failure. Thanks to the non-volatile memory registers of the PIC16F887, it continually tracks a record of the values that are set on the Voltage and Current knob.
Summing up the above points, TEKPOWER TP3005T DC Power supply perfectly fits for people who are in interested in experimenting electronics and Do It Yourself projects. Being a basic model power supply, it has notable features like Over Current Protection (OCP), Over Heat Protection, clickable control knobs and compact form factor. The embedded programming of PIC16F887 from Microchip works perfectly fine. It accurately sends and receives signals during the operation of the power supply without any delays and errors. Even though the operating voltage range is limited to certain power outlets, it provides better efficiency. The Precision of this entry-level power supply is really an appreciable one. Overall, it is very good and suggested for buying.