Posts by Ben (Page 2)

You are currently viewing a selection of posts from the Pololu Blog. You can also view all the posts.

Popular tags: community projects new products raspberry pi arduino more…

New 5:1 Glideforce light-duty linear actuators

Posted by Ben on 21 May 2019
Tags: new products

We have filled out our line of 5:1 Glideforce Light-Duty Linear Actuators to include all of Concentric’s available lengths by adding 2″, 6″, 8″, and 10″ versions, with and without feedback, to our existing 4″ and 12″ options. The low gear ratio makes these our fastest (but weakest) linear actuators, capable of lifting up to a few dozen pounds at speeds up to 1.7″ per second (44 mm/s) at 12 V. For stronger but slower options, we have versions available with a 10:1 gear ratio or 20:1 gear ratio.

This brings our total selection of light-duty actuators to 36 options:

Actuator
Type
Max
Dynamic
Load
No-Load
Speed
@ 12 V
Max-Load
Speed
@ 12 V
Current
Draw
@ 12 V
Nominal
Stroke
Length
With
Feedback
Without
Feedback
Light-Duty
(LD) 5:1
15 kgf
[34 lbs]
4.4 cm/s
[1.7″/s]
3.6 cm/s
[1.4″/s]
1.2 A –
3.2 A
2″ LACT2P-12V-05 LACT2-12V-05
4″ LACT4P-12V-05 LACT4-12V-05
6″ LACT6P-12V-05 LACT6-12V-05
8″ LACT8P-12V-05 LACT8-12V-05
10″ LACT10P-12V-05 LACT10-12V-05
12″ LACT12P-12V-05 LACT12-12V-05
Light-Duty
(LD) 10:1
25 kgf
[55 lbs]
2.8 cm/s
[1.1″/s]
2.3 cm/s
[0.9″/s]
1.2 A –
3.2 A
2″ LACT2P-12V-10 LACT2-12V-10
4″ LACT4P-12V-10 LACT4-12V-10
6″ LACT6P-12V-10 LACT6-12V-10
8″ LACT8P-12V-10 LACT8-12V-10
10″ LACT10P-12V-10 LACT10-12V-10
12″ LACT12P-12V-10 LACT12-12V-10
Light-Duty
(LD) 20:1
50 kgf
[110 lbs]
1.5 cm/s
[0.57″/s]
1.2 cm/s
[0.48″/s]
1.2 A –
3.2 A
2″ LACT2P-12V-20 LACT2-12V-20
4″ LACT4P-12V-20 LACT4-12V-20
6″ LACT6P-12V-20 LACT6-12V-20
8″ LACT8P-12V-20 LACT8-12V-20
10″ LACT10P-12V-20 LACT10-12V-20
12″ LACT12P-12V-20 LACT12-12V-20

New products: ACS724 current sensor carriers

Posted by Ben on 17 May 2019
Tags: new products

We now have new current sensors based on Allegro’s ACS724, the successor to the ACS714 that we have been using for many years. The ACS724 offers a number of exciting improvements over the ACS714, including more current range options (up to ±50 A!), over twice the sensitivity for the ±5 A version, a higher bandwidth for faster response times, and differential Hall sensing for substantially reduced interference from ambient magnetic fields. In quick tests, we saw a variation of around 1% of the full range just from changing the orientation of the ACS714 in space (because of the Earth’s magnetic field), while the ACS724 output stayed steady regardless of orientation. We also tried bringing a small magnet close to each sensor, and its effect on the output was many times smaller on the ACS724.

These bidirectional and unidirectional current sensors are a simple way to gain fundamental insight into the performance of your system. You can use them for closed-loop torque control of actuators, tracking power consumption over time, or even as inexpensive current probes for an oscilloscope. They output an analog voltage that varies linearly with the current passing through them, and because they use the Hall effect to measure the current, they offer full electrical isolation of the current path from the sensor’s electronics. This method of sensing means the sensor can be inserted anywhere into the current path, including on the high side, and because their current path resistance is on the order of 1 mΩ or less, they have minimal effect on the rest of the system.

Five different current ranges are available:

Together with the Broadcom ACHS-712x current sensors we released last month, this brings our full current sensor lineup to thirteen sensors:


ACS709 Current
Sensor Carrier

ACS711EX Current
Sensor Carriers

ACS714 Current
Sensor Carriers

ACS724 Current
Sensor Carriers

ACHS-712x Current
Sensor Carriers
Sensor IC: ACS709 ACS711EX ACS714 ACS724 ACHS-712x
Current range / sensitivity(1): ±75 A / 28 mV/A ±15.5 A / 136 mV/A
±31 A / 68 mV/A
±5 A / 185 mV/A
±30 A / 66 mV/A
0–⁠10 A / 400 mv/A
0–⁠30 A / 133 mV/A
±5 A / 400 mV/A
±20 A / 100 mV/A
±50 A / 40 mV/A
±10 A / 185 mV/A
±20 A / 100 mV/A
±30 A / 66 mV/A
Path resistance: 1.1 mΩ 0.6 mΩ 1.2 mΩ 1.2 mΩ 0.7 mΩ
Bandwidth 120 kHz 100 kHz 80 kHz 120 kHz 80 kHz
Vcc range:(1) 3 V–5.5 V 3 V–5.5 V 4.5 V–5.5 V 4.5 V–5.5 V 4.5 V–5.5 V
Size: 0.82″ × 0.9″ 0.7″ × 0.8″ 0.7″ × 0.8″ 0.7″ × 0.8″ 0.7″ × 0.8″
Special features: configurable
over-current threshold,
low-voltage operation,
high bandwidth
over-current fault pin,
low-voltage operation
Differential Hall sensing
rejects common-mode fields,
high bandwidth
1-piece price: $14.95 $3.95 $19.95 $11.95 $6.95
1 Sensitivity based on when Vcc is 5V.

Introductory special

As usual, we are offering an extra introductory special discount on the ACS724 current sensor carriers, to help share in our celebration of releasing a new product. The first hundred customers to use coupon code ACS724INTRO can get up to five units for just $5.55 each!

New products: D36V28Fx Step-Down Voltage Regulators

Posted by Ben on 12 April 2019
Tags: new products

I am happy to announce the release of our newest regulators, the D36V28Fx family of step-down voltage regulators. These regulators support a wide input voltage range (up to 50 V!) and can deliver up to 4 A, making them well suited for use with power-hungry processors like the Raspberry Pi and projects involving servos or small motors.

Step-Down Voltage Regulator D36V28Fx, assembled on breadboard.

Step-Down Voltage Regulator D36V28Fx, bottom view with dimensions.

The family consists of six fixed output voltage versions between 3.3 V and 12 V:

And since we make these ourselves here in Las Vegas, we can also quickly make versions with custom output voltages; please contact us us for more information.

Comparison to the D24V22Fx step-down regulator family

Top view of D36V28Fx step-down voltage regulator.

Top view of D24V22Fx step-down voltage regulator.

The D36V28Fx family now becomes our recommended alternative to the slightly smaller D24V22Fx if you need a little more power or operation above 36 V:

Comparison of the maximum continuous current of Step-Down Voltage Regulators D36V28Fx and D24V22Fx.

The D24V22Fx still outperforms the D36V28Fx when it comes to dropout voltage and quiescent current:

Comparison of the dropout voltage of Step-Down Voltage Regulators D36V28Fx and D24V22Fx.

Comparison of the quiescent current of Step-Down Voltage Regulators D36V28Fx and D24V22Fx.

Introductory special

As usual, we are offering an extra introductory special discount on these new regulators, to help share in our celebration of releasing a new product. The first hundred customers to use coupon code D36V28XINTRO can get up to three units for just $7.77 each!

New Tic T500 revision to address problem with missed steps

Posted by Ben on 18 January 2019
Tags: tic
New Tic T500 revision to address problem with missed steps

One of the fun things you learn as an engineer is that physically laying out a circuit requires a lot more than simply confirming it matches the schematic. In practice, there are many more things to think about, and if you’ve seen datasheets with layout guidelines or recommendations, you’re probably aware of some of them. (Thermal considerations, adequate decoupling, minimizing parasitic inductance and capacitance…) What’s more, these considerations are often in conflict (e.g. is it better to have the decoupling capacitor closer to the IC or to have a wider trace for that high-current path?), and trouble can arise if you don’t correctly assess their relative importance. That is what happened to us with our Tic T500 stepper motor controller, where the location of a specific decoupling capacitor ended up being far more significant than we had anticipated. Continued…

New product: STSPIN220 Low-Voltage Stepper Motor Driver Carrier with 1/256 microstepping

Posted by Ben on 16 January 2019
Tags: new products

I am happy to announce our first new product of 2019, a carrier board for the STSPIN220 stepper motor driver, which operates all the way down to 1.8 V, making it our lowest-voltage stepper motor driver. And like its higher-voltage sibling, the STSPIN820 that we released a few months ago, it offers microstepping down to 1/256 steps. This new carrier board has the same 16-pin, 0.6″ × 0.8″ form factor as our other popular stepper motor drivers, and as with our STSPIN820 carrier, it inverts the enable input so that it has the more familiar functionality of those drivers (but be careful not to pop these into a 12 V or 24 V socket!).

By the way, keep in mind that you do not necessarily need a low-voltage stepper motor driver just because your stepper motor has a low rated voltage. The voltage rating is just the voltage at which your stepper motor will draw its rated current, and it’s really the current rating that you need to be careful about if you want to avoid damaging your stepper motor. All of our stepper motor drivers let you limit the maximum current, so as long as you set the limit below the rated current, you will be within spec for your motor, even if the voltage exceeds the rated voltage. In general, using a high supply voltage along with active current limiting allows for better performance, so the main reason for using a low-voltage stepper motor driver like the STSPIN220 is if your supply voltage is constrained to some low value by some other aspect of your system.

This new release brings our selection of stepper motor drivers in this compact form factor to eleven:


A4988
(original)

A4988,
Black Ed.

DRV8825

DRV8834

DRV8880

MP6500,
Pot. CC

MP6500,
Digital CC

TB67S279­FTG

TB67S249­FTG

STSPIN­820

STSPIN­220
Driver chip: A4988 DRV8825 DRV8834 DRV8880 MP6500 TB67S279­FTG TB67S249­FTG STSPIN­820 STSPIN­220
Min operating voltage: 8 V 8.2 V 2.5 V 6.5 V 4.5 V 10 V 10 V 7 V 1.8 V
Max operating voltage: 35 V 45 V 10.8 V 45 V 35 V 47 V 47 V 45 V 10 V
Max continuous current per phase:(1) 1 A 1.2 A 1.5 A 1.5 A 1 A 1.5 A 1.1 A 1.6 A 0.9 A 1.1 A
Peak current per phase:(2) 2 A 2.2 A 2 A 1.6 A 2.5 A 2 A 2 A 4.5 A 1.5 A 1.3 A
Microstepping down to: 1/16 1/32 1/32 1/16 1/8 1/32 1/32 1/256 1/256
Board layer count: 2 4 4 4 4 4 4 4 4 4
Special features: high current low-voltage
operation,
high current
AutoTune,
digital current
reduction
high current digital current
control,
high current
Auto Gain Control,
ADMD,
high max voltage
Auto Gain Control,
ADMD,
high max voltage,
high current
128 and 256
microsteps,
high max
voltage
64, 128, and
256 microsteps,
low-voltage
operation
1-piece price: $13.95 $14.95 $15.95 $7.95 $8.95 $6.95 $6.95 $10.75 $12.95 $14.95 $7.95
1 On Pololu carrier board, at room temperature, and without additional cooling.
2 Maximum theoretical current based on components on the board (additional cooling required).

Last year, we began offering introductory specials to celebrate each newly released product, and we are continuing with that this year: the first 100 customers that use coupon code STSPIN220INTRO can get up to five units at just $3.77 each.

New products: 16-channel QTR MD reflectance sensor arrays

Posted by Ben on 28 December 2018
Tags: new products

QTR-MD-16A Reflectance Sensor Array.

We now have 16-sensor, medium-density (8mm-pitch) versions of our new QTR reflectance sensor arrays. Like the versions already released, these new modules are available in analog and RC configurations and with two different sensor types, resulting in four new products in all:

Unlike the medium-density (MD) arrays we have released previously, which just use the high-density PCBs in partially populated configurations, these new 16-channel modules use PCBs specifically designed for an 8 mm pitch. As a result, these are the first MD versions that allow separate control of the odd and even emitters, which gives you extra options for detecting light reflected at various angles. They have the same board dimensions (125 × 16.5 mm) and mounting hole locations as the high-density (4mm-pitch) 31-channel arrays, but the pinout is different.

QTR-MD-16A Reflectance Sensor Array.

QTR-HD-31A Reflectance Sensor Array.

For more information on our new QTR sensor family, you can see some of our previous blog posts about the versions we have already released:

Don’t forget to get in on our QTR introductory promotion! Be one of the first 100 customers to use coupon code QTRINTRO and get any of these new sensors at half price! (Limit 3 per item per customer.)

(A little more than) twelve days of Christmas sale

Posted by Ben on 4 December 2018



If you missed our Black Friday sale or realize you didn’t quite get everything you wanted, don’t fret: we have all active Pololu-brand and PCX products on sale for 12% off, and we are offering 15% off twelve broad categories of our products. The sale runs through Friday, December 21, but be careful to order early for delivery before Christmas. Save on your Christmas shopping, or stock up now on robot parts for the new year. Check out the sale page for all the discounts and coupon codes. Merry Christmas!

Last call for Cyber Monday savings!

Posted by Ben on 26 November 2018


Things are slowing down in our warehouse as our biggest sale of the year winds down, and to all those who have ordered, thank you! There’s still time for you to get in on today’s deals if you haven’t already, but don’t wait too much longer: the deals end at midnight Pacific time.

Cyber Monday at Adafruit

Posted by Ben on 26 November 2018


Our friends at Adafruit are also having a Cyber Monday sale, with 20% off on their CircuitPython product line and 15% off sitewide. See their blog post for more details!

Our Black Friday/Cyber Monday sale is going strong, and happy Thanksgiving from Romi Turkey

Posted by Ben on 23 November 2018


Our biggest sale of the year is underway, and manufacturing and shipping are working hard to make your robot parts and ship them out. You’ve done a fantastic job challenging them so far, but they’ve still managed to keep up with our same-day shipping guarantee, even though we have suspended that during the sale. Let’s keep up the pressure and challenge them even more as the sale goes on!

There will be no doorbusters this weekend, just great deals on lots of products all weekend long. Doorbusters will return Monday morning, the last day of the sale.

Now, for something else fun: in the spirit of Thanksgiving, we dressed a Romi robot up as a Turkey. Enjoy!

New Products

Motoron M3H550 Triple Motor Controller for Raspberry Pi (No Connectors or Standoffs)
3.3V, 2.5A Step-Up/Step-Down Voltage Regulator S13V25F3
3pi+ 2040 Control Board
VL53L7CX Time-of-Flight 8×8-Zone Wide FOV Distance Sensor Carrier with Voltage Regulator, 350cm Max
Motoron M3S550 Triple Motor Controller Shield for Arduino (Connectors Soldered)
3pi+ 2040 Robot - Turtle Edition (75:1 LP Motors), Assembled
7.5V, 2.5A Step-Up/Step-Down Voltage Regulator S13V25F7
6V Step-Up/Step-Down Voltage Regulator S8V9F6
MinIMU-9 v6 Gyro, Accelerometer, and Compass (LSM6DSO and LIS3MDL Carrier)
Ribbon Cable Premium Jumper Wires 10-Color F-F 60" (150 cm)
Log In
Pololu Robotics & Electronics
Shopping cart
(702) 262-6648
Same-day shipping, worldwide
Menu
Shop Blog Forum Support
My account Comments or questions? About Pololu Contact Ordering information Distributors