# Global Specialties PB-503A Circuit Design Trainer # Global Specialties PB-503A Circuit Design Trainer ## Key Features At A Glance - Triple-output DC power supply: fixed +5VDC at 1.0A and variable ±1.3 to ±15VDC at up to 500mA with ripple under 5mV - Built-in digital function generator covering 0.1 Hz to 100 kHz with sine, square, triangle, and TTL outputs - Removable PB-3 solderless breadboard plate with 2,520 tie-points plus 200 bus-strip tie-points connected to the supply rails - 16 logic indicator LEDs with selectable TTL/+5V or CMOS thresholds, plus an 8-channel logic monitor - Two debounced pushbutton pulsers (each with normally-open and normally-closed outputs) and eight logic switches for digital test stimulus - Uncommitted lab resources on the panel: 1 kΩ and 10 kΩ potentiometers, two SPDT switches, two BNC connectors, and an 8Ω/0.25W speaker - Switchable AC line input: 115 VAC at 60 Hz or 230 VAC at 50 Hz, backed by a 3-year warranty The Global Specialties PB-503A is a self-contained circuit design trainer that combines a solderless breadboard work surface with the lab resources most often needed to bring an electronics experiment to life: a triple-output DC power supply, a digital function generator, logic switches and indicators, debounced pulsers, uncommitted potentiometers, BNC connectors, and an audio speaker. The datasheet positions the PB-503A as a robust platform suitable for all levels of electronics instruction and design, intended to give students hands-on breadboarding experience while remaining capable enough for experienced designers working on demanding projects. The applications listed on the datasheet span the full range of analog, digital, and microprocessor circuit work the trainer is designed to support. Opto-device circuits, clocks, multivibrators, oscillator circuits, timers, and function generator circuits exercise the analog and timing resources. Logic circuits, gates, counters, flip-flops, analog-to-digital and digital-to-analog converters, and medium-scale integration circuits exercise the digital section. Phase lock loops and operational amplifier work draw on the combined analog and digital capabilities of the platform. ## Brand Heritage Global Specialties has been a long-established name in solderless breadboarding and electronics training equipment. The PB-503A datasheet carries a 2021 copyright notice from Cal Test Electronics, Inc., reflecting the brand's current corporate ownership and shared distribution with the broader Cal Test test-accessory line. ## Product Core & Specifications Specification PB-503A AC Line Input 115 VAC @ 60 Hz or 230 VAC @ 50 Hz (switchable) Power Supplies Fixed DC: +5 VDC 1.0 A max. (current limited); Ripple <5 mV. Variable + DC: +1.3 VDC ±0.05 V @ 150 mA to +15 VDC @ 500 mA, Ripple < 5 mV. Variable - DC: -1.3 VDC ±0.05 V @ 150 mA to -15 VDC @ 500 mA, Ripple < 5 mV Binding Posts 4: Ground, +5 VDC, Variable ±VDC Power Supply Outputs Pulsers 2 Pushbutton-operated, open-collector output pulsers. Each with 1 normally-open, 1 normally closed output. Each output sinks up to 250 mA Digital Function Generator Frequency Range: 0.1 Hz to 100 kHz, two ranges. Output Voltage: 0 to +10Vp-p into 600 Ω Load (20 Vp-p in open circuit), short circuit protected. Output Impedance: 600 Ω except TTL. Output waveforms: Sine, Square, Triangle & TTL. Sine Wave Distortion: <3% @ 1 kHz Typical. TTL Pulse: Rise & fall time: <25 ns, drive 100 TTL. Square Wave: Rise and fall times <0.5 μs Logic Switches 8 Logic Switches select Logic High and Logic Low. Logic Low Level: Ground. Logic High Level: Switchable between +5 V and the variable positive power supply Switches 2 Single Pole Double Throw (SPDT) - uncommitted Logic Indicators LEDs: 16 LEDs; 8 red to indicate logic high and 8 green to indicate logic low. Logic High Threshold: 2.2 V (nominal) in TTL/+5 V mode, 70% (nominal) of selected operating voltage in CMOS mode. Logic Low Threshold: 0.8 V (nominal) in TTL/+5 V mode, 30% (nominal) of selected operating voltage in CMOS mode Connectors 2 BNC - uncommitted Potentiometers 2: 1 kΩ and 10 kΩ - uncommitted Speaker 8 Ω, 0.25 W - uncommitted Breadboards Removable plexiglas socket plate (PB-3) with 2,520 tie-points with 200 additional bus strip tie-points internally connected to power supply outputs and ground Weight 7 lbs (3.2 kg) Dimensions 6.5 x 12.75 x 10 in (16.5 x 32.4 x 25.4 cm) (H x W x D) Warranty 3 Years **Important:** Specifications apply after a 20-minute temperature stabilization period over an ambient range of 20 °C ± 5 °C, and AC line input must be set to match local mains (115 VAC at 60 Hz or 230 VAC at 50 Hz) via the rear-panel selector before power-on.**Important:** All specifications apply to the unit after a temperature stabilization time of 20 minutes over an ambient range of 20 °C ± 5 °C.**Important:** AC line input is switchable between 115 VAC @ 60 Hz and 230 VAC @ 50 Hz using the rear-panel line input selector. Verify the selector position matches your local mains voltage before applying power.Recommended pairing: the PB-3 solderless breadboard plate and the GSC-2311KIT accessories kit, both listed on the PB-503A datasheet as compatible classroom resources for extending lab inventory and supporting shared-bench instruction. **Please review the Manufacturer's Data Sheet to verify published specifications. Feedback on this webpage is always welcome — please reach out to your Test Architect at any time for questions or concerns. Thank you, we truly appreciate you being our customer.** ## Details - **Price:** 740.0 USD - **Vendor:** Global Specialties - **Type:** Trainer - **Tags:** Global Specialties, Manufacturers, Other Equipment, product_manual_group_3, Product_new, Workstation ## Variants | Variant | Price | Available | |---------|-------|-----------| | Default Title | 740.00 USD | In stock | ## Images - PB-503A Global Specialties Workstation --- > Source: [ValueTronics](https://valuetronics.com/products/pb-503a-global-specialties-workstation-new) > Updated: 2026-05-30