Equipment

Lab Equipment

The Srivastava Senior Design Lab has a wide selection of equipment that provides nearly all of the capabilities of the other ECE teaching labs in one place. Although the equipment may not be identical to that found in these other teaching labs, similar functionality is offered. Use the experience of learning new equipment as a way to expand your horizons. If you are using a piece of equipment for the first time, ask a TA for assistance, to make sure you understand how to safely use it. If the available equipment does not meet the needs of your project, talk to the course staff, and we will help you find what you need elsewhere on campus, consider purchasing it for the senior design lab (if it would be used by many groups), or brainstorm alternate ways to solve your problem.

Lab Kits

Each team is provided with at least one lockable storage drawer in the lab as well as a portable lab kit. An additional drawer and/or kit may be issued as need arises and facilities allow.

The lab kit includes a box with carrying handle and contains a wiring board for prototyping circuit projects, a multiple-output power supply, a digital multimeter, and a set of 8 cables (2 bnc/bnc, 2bnc/pin, 2 banana/banana, and 2 banana/pin). This is checked out to you by your TA at the beginning of the semester and must be returned undamaged at the end of the semester. Missing lab kits will result in an encumbrance or withheld diploma and a charge of $500.00, so always be sure to lock your lockers! Also, do not store any cables from the lab in your kit. Doing so will result in a loss of points.

Test Equipment

Most equipment is connected to the PCs via HPIB cables. Below is a sampling of the test equipment available:

Specific setups at the various lab benches can be in the listing at the bottom of this page.

Computers

The lab has PCs with enough processing power for the needs of nearly any senior design project. These machines are networked to a high-capacity laser printer (printing will count against your standard print quota). Each has an Ethernet connection to the campus network, an HPIB interface card connecting it to all of the standard instruments on its bench, and a sound card. The computers are maintained by Engineering IT, located in 3080 ECE Building.

The PCs are presently configured with the software shown here. Their primary uses include:

Test Equipment (Listed by lab bench)

 
Bench: A
Oscilloscope Rohde & Schwarz RTE 1054
Digital Multimeter Keysight 34461A
Triple Output DC Power Supply Keysight E3631A
Waveform Generator Agilent 33500B Series
 
Bench: B
Oscilloscope Agilent DSO7104B
Digital Multimeter Keysight 34461A
Triple Output DC Power Supply Keysight E3631A
Waveform Generator Agilent 33500B Series
 
Bench: C
Oscilloscope Agilent DSO-X 3034A
Digital Multimeter Keysight 34461A
Triple Output DC Power Supply Keysight E3631A
Waveform Generator Agilent 33500B Series
Pulse Generator Hewlett-Packard 8011A
Dual Output Power Supply Hewlett-Packard 6234A
 
Bench: D (Power)
Oscilloscope Agilent DSO-X 6004A
Digital Multimeter Keysight 34461A
Triple Output DC Power Supply Keysight E3631A
Waveform Generator Agilent 33500B Series
Pulse Generator Hewlett-Packard 8011A
Triple Output Power Supply Hewlett-Packard 6235A
Digital Power Analyzer Valhalla Scientific 2101
DC Power Supply Hewlett-Packard 6632A
DC Electronic Load Agilent 6060B
kW Power Supply Sorensen DCS 20-50
 
Bench: E
Oscilloscope Agilent DSO-X 3034A
Digital Multimeter Keysight 34461A
Triple Output DC Power Supply Keysight E3631A
Waveform Generator Agilent 33500B Series
Pulse Generator Hewlett-Packard 8011A
 
Bench: F
Oscilloscope and Logic Analyzer Teledyne LeCroy HDO 4054-MS
Digital Multimeter Keysight 34461A
Triple Output DC Power Supply Keysight E3631A
Waveform Generator Agilent 33500B Series
Pulse Generator Hewlett-Packard 8011A
 
Bench: G (power)
Oscilloscope Agilent DSO-X 6004A
Digital Multimeter Keysight 34461A
Triple Output DC Power Supply Keysight E3631A
Waveform Generator Agilent 33500B Series
Triple Output Power Supply Hewlett-Packard 6235A
DC Power Supply Hewlett-Packard 6632A
DC Electronic Load Hewlett-Packard 6060B
Current Probe Amplifier Tektronix AM 503
 
Bench: H (RF)
Mixed Domain Oscilloscope Tektronix MDO4054B-3
Digital Multimeter Keysight 34461A
Triple Output DC Power Supply Keysight E3631A
Waveform Generator Agilent 33500B Series
S-Parameter Network Analyzer Hewlett-Packard 8753ES
S-Parameter Test Set Hewlett-Packard 85047A
Pulse Generator Hewlett-Packard 8011A
Signal Generator Hewlett-Packard 8657B
 
Bench: I
Oscilloscope Agilent DSO7104B
Digital Multimeter Keysight 34461A
Triple Output DC Power Supply Keysight E3631A
Waveform Generator Agilent 33500B Series
Pulse Generator Hewlett-Packard 8011A
Dual Output Power Supply Hewlett-Packard 6234A
 
Bench: J (RF)
Oscilloscope Agilent DSO7104B
Digital Multimeter Keysight 34461A
Triple Output DC Power Supply Keysight E3631A
Waveform Generator Agilent 33500B Series
Triple Output Power Supply Hewlett-Packard 6235A
DC Power Supply Hewlett-Packard 6632A
Network Analyzer Hewlett-Packard 8751A
S-Parameter Test Set Hewlett-Packard 87511A
 
Bench: K
Oscilloscope and Logic Analyzer Teledyne LeCroy HDO 4054-MS
Digital Multimeter Keysight 34461A
Triple Output DC Power Supply Keysight E3631A
Waveform Generator Agilent 33500B Series
Dual Output Power Supply Hewlett-Packard 6234A
 
Bench: L (RF)
Mixed Domain Oscilloscope Tektronix MDO4054B-3
Digital Multimeter Keysight 34461A
Triple Output DC Power Supply Keysight E3631A
Waveform Generator Agilent 33500B Series
Vector Signal Analyzer Agilent 89441A
RF Section Hewlett-Packard 89440A
Signal Generator Hewlett-Packard 8657B
Precision LCR Meter Hewlett-Packard 4284A
 
Bench: M
Oscilloscope Agilent DSO7104B
Digital Multimeter Keysight 34461A
Triple Output DC Power Supply Keysight E3631A
Waveform Generator Agilent 33500B Series
 
Bench: N
Oscilloscope Agilent DSO-X 3034A
Digital Multimeter Keysight 34461A
Triple Output DC Power Supply Keysight E3631A
Waveform Generator Agilent 33500B Series
 
Bench: O
Oscilloscope Agilent DSO-X 3034A
Digital Multimeter Keysight 34461A
Triple Output DC Power Supply Keysight E3631A
Waveform Generator Agilent 33500B Series
Pulse Generator Hewlett-Packard 8011A
Triple Output Power Supply Hewlett-Packard 6235A
Communications Receiver AOR AR5000
 
Bench: P
Oscilloscope Agilent DSO-X 3034A
Digital Multimeter Keysight 34461A
Triple Output DC Power Supply Keysight E3631A
Waveform Generator Agilent 33500B Series

Multipurpose Temperature Controlled Chamber (for Consumer Applications)

Isaac Brorson, Stefan Sokolowski, Mitchell Stermer

Multipurpose Temperature Controlled Chamber (for Consumer Applications)

Featured Project

Multipurpose Temperature Controlled Chamber (for Consumer Applications)

#TEAM MEMBERS:

Stefan Sokolowski (stefans2)

Mitchell Stermer (stermer2)

Isaac Brorson (brorson2)

#PROBLEM:

Have you ever put a drink in the freezer to make it cool down faster, only to forget about it and later find it exploded and frozen?

Or have you wanted to cook a steak, but forgotten to move it from the freezer to the refrigerator the previous day?

Finally, has there ever been a time when you set food out overnight in order to prepare it for the next day but only to find that it didn’t thaw as expected?

We have done all of these things plus more and have always wished there were a smart device that could quickly cool or warm food without freezing or cooking it.

#SOLUTION:

Our project would be a programmable temperature controlled chamber which allows a user to set the temperature curve of a food item they are planning on consuming in the near future. This device would be able to quickly heat or cool food to a desired temperature, then hold it at that temperature until the user is ready to use the food. The way someone would use this device would start by placing their food item in the device's insulative chamber and closing the door. The user interface would present the user with a variety of options: standard heating or cooling presets for common food items, temperature set and hold, or the ability to set a detailed temperature curve.

If you want to cool a drink to just above freezing, you would select the corresponding menu option, and this device will lower the temperature of its chamber to well below freezing, then slowly raise its temperature to ensure the drink doesn't freeze.

If you select the menu option to thaw a steak, this device will raise the temperature of the chamber to just below the point at which meat begins to cook, (roughly 105 degrees F) then slowly lower the temperature towards room temperature.

This device could also be used for applications outside of cuisine. Say you’re running an experiment to test the capacity of a battery at different temperatures. You could set a temperature curve to visit several different temperatures and hold each one as your battery capacity tester runs its tests. This would allow you to automate an experiment that would otherwise require intermittent attention over the span of multiple hours.

There are temperature controlled chambers on the market, but they’re all exorbitantly expensive and large for a household kitchen. We want to make a device that could sit on a countertop and be affordable to anyone who has the budget for other standard kitchen appliances.

![pic](https://i.imgur.com/HJiCQsN.png)

#POWER

We plan to use a dual output DC power supply such as the RD-125B[1] to power both our digital electronics and the high power heating and cooling elements. This power supply would be plugged directly into an outlet using a 120V plug, and would create 5V and 24V DC outputs. According to its datasheet[1], the RD-125B’s 24V output is rated to supply 4.6A, which equates to just over 110W. Based on our research of thermoelectric coolers and heating elements, we think this should be plenty of power for our application.The RD-125B’s 5V output is rated to supply far more power than our 5V electronics could possibly draw.

#MECHANICAL DESIGN

In order to reach temperatures below freezing with thermoelectric coolers, we’ll need to thermally insulate the chamber very well. Since this insulation needs to be able to withstand the heat produced by the heating elements, we landed on Kaowool. This ceramic wool insulates very well while also being rated to over 1000℃[2].

Since our device is intended for food applications, it’s important for our temperature controlled chamber to be waterproof and food safe. For this reason, we plan to purchase an off-the-shelf cooking pot such as this one[3]. By fitting a smaller pot inside of a slightly larger pot, we can create an affordable and convenient way to insulate our chamber. We can fit the gap between the pots with Kaowool insulation, and use the larger pot’s lid with Kaowool in it to seal the top.

To heat the chamber, we plan to wrap a resistive heating element (such as nichrome wire) around the inner chamber. Since we plan to use an electrically conductive pot for our inner chamber, we’ll need to insulate the heating element from it to prevent shorting. This can be done with Kapton tape, which can withstand temperatures ranging from -269℃ to 400℃[4].

To cool the chamber, we plan to use thermoelectric cooling modules. These require a good thermal pathway to work well, so we’ll need to use a material with high thermal conductivity to mount them to the chamber wall. We plan to ask the machine shop to machine us aluminum mounts which match the curved outside surface of the pot composing the chamber to the flat faces of the thermoelectric cooling elements. Additionally, we’ll use thermal grease to reduce the thermal resistance of the junctions. The thermoelectric coolers will require rectangular holes cut through the wall of the outer pot so they can pump heat to outside of the device.

We plan to mount our circuit board and the user interface electronics in an E-box attached to the side of the outer pot. We can use standoff rods to ensure the electronics don’t get heated or cooled too much from being close to the chamber, though we expect that our thermal insulation will be good enough for that not to be a concern.

#HEATING SUBSYSTEM

As mentioned in mechanical design, we plan to use a resistive heating element to heat the chamber. This will be powered by the higher voltage DC power rail produced by the power supply, which is 24V for the RD-125B. We'll use a solid state switch to control the current through the heating element. This allows us to control its power using PWM, which is essential for ensuring the chamber temperature remains below a certain prescribed level.

The simplest and most cost effective switching device would be an N-channel power MOSFET such as the Taiwan Semiconductor TSM170N06CH[5].

#COOLING SUBSYSTEM

We plan to use thermoelectric (Peltier) coolers to provide the cooling. These work as heat pumps, so we’ll need heat sinks and cooling fans to dissipate the heat they produce. The thermoelectric coolers and fans will be run off of the same higher voltage DC that powers the heating element.

We want to have the option to run the thermoelectric coolers in reverse while the chamber is heating to prevent their heat sinks from cooling down the chamber. To do this we’ll need to power the thermoelectric coolers through an H-bridge so that we can reverse their polarities. The H-bridge can be composed of two N-channel MOSFETs such as the one mentioned above[5], and two P-channel MOSFETs such as the Rectron Semiconductor RM15P55LD[6]. The H bridge can be controlled by the STM32 microcontroller, allowing us to use PWM to vary the power supplied to the thermoelectric coolers. We may or may not need gate drivers for the H-bridge. Gate drivers are necessary for a fast switching rate, but our application doesn’t require high frequency PWM.

#TEMPERATURE MEASUREMENT SUBSYSTEMS

To be as precise as possible, we want distinct temperature sensors for measuring the temperature of the air in the chamber and the temperature of the item being warmed or cooled. Measuring the temperature of the food is made difficult due to many food items having insulative packaging. (Glass bottles, styrofoam containers, etc...) Since we want our device to work for as wide of a range of food items as possible, we plan to give the user the option to select from multiple different interchangeable food temperature probes. Temperature sensing probes could include a meat thermometer, a flat metallic probe that could be placed on frozen meat, or a ring shaped thermometer that could go around a bottle or can.

Temperature sensing (thermocouple / thermopile) may require some basic analog electronics, such as an op amp to amplify the small voltage produced by a thermocouple.

#USER INTERFACE SUBSYSTEM

We plan to use an STM32 microcontroller, for our use a STM32F103C8T6 would probably suffice with IO and processing power, but more capable F4’s might be considered if we add more sensors. The microcontroller and user interface will require logic level voltage DC.

We would most likely use an I2C enabled LCD display as well as a bright, external RGB LED in order to show the user what state the machine is in from a distance. We plan to use a push button rotary encoder to allow the user to interact with the device, in addition to an ON/OFF switch and a "cancel" button. User feedback should be fairly simple and if time allows, we might consider connecting the device to an external service to send users notification as to the status of their heating/cooling cycle.

The user interface screen will have multiple interactive menus: one to select the behavior mode of the device, one to set temperature and time values, one to show a temperature curve, and one to be displayed while the device is operating.

#CHALLENGES & CONSIDERATIONS:

- Everything inside the chamber will need to be able to withstand the full range of temperature.

- Electronics will need to be very well thermally insulated from the chamber if we want to use it as an oven.

- Since thermopiles operate off of a temperature gradient, they require a stable case temperature. This means we'll need to keep the thermocouple in a temperature controlled environment.

- The chamber should ideally be made watertight for the case of a spill or leak.

- When making the mechanical design, we'll need to keep in mind how different materials expand / contract at different rates when they're heated / cooled.

#CRITERION FOR SUCCESS:

- Inside of the chamber should be able to reach at a low end 0 degrees Celsius and at a high end 40 degrees Celsius.

- Be able to hold temperature to within +-5 degrees Celsius of target temperature.

- User has the ability to set target temperature, heating/cooling curve and max/min temperature allowances through GUI on an LCD display.

- Display of current temperature, and possibly a plot of the temperature vs. time graph.

- Ability to select the behavior of the device from a provided menu of presets for different foods.

- (Stretch Goal) We could possibly include multiple different methods to measure food temperature in addition to the ambient temperature. (Stainless steel probe to measure the internal temperature of meats, thermocouple for bottles and containers)

[1] Power Supply:

https://www.mouser.com/datasheet/2/260/RD_125_SPEC-1511572.pdf

[2] Kaowool:

https://www.morganthermalceramics.com/media/llhhadih/5-14-205_kaowoolblankets_072018.pdf

[3] Aluminum pot: https://www.amazon.com/Winco-Winware-Aluminum-Stockpot-12-Quart/dp/B001CHMIQ4/ref=sr_1_10?crid=1VECOQHCN2UC2&keywords=aluminum%2Bpot&qid=1706684643&sprefix=aluminum%2Bpot%2Caps%2C93&sr=8-10&th=1

[4] Kapton tape:

https://www.dupont.com/electronics-industrial/kapton-hn.html#:~:text=Kapton%C2%AE%20HN%20has%20been,C%20(752%C2%B0F).

[5] N channel MOSFET:

https://services.ts.com.tw/storage/resources/datasheet/TSM170N06CH_A2211.pdf

[6] P channel MOSFET:

https://www.mouser.com/datasheet/2/345/rm15p55ld-1396325.pdf

Project Videos